政院國家科學委員會專題研究計畫成果報告ir.lib.ncku.edu.tw/bitstream/987654321/139069/1/兆赫波波導及波導型感測器之... · 關鍵詞：兆赫波、次毫米波、兆赫波光纖、光纖感測器。

行政院國家科學委員會專題研究計畫成果報告

兆赫波波導及波導型感測器之特性研究

研究成果報告(精簡版)

計畫類別個別型

計畫編號 NSC 97-2218-E-006-013-

執行期間 97年 03 月 01 日至 98年 10 月 31 日

執行單位國立成功大學光電科學與工程研究所

計畫主持人呂佳諭

計畫參與人員助理教授-主持人(含共同主持人)呂佳諭

報告附件出席國際會議研究心得報告及發表論文

處理方式本計畫可公開查詢

中華民國 98年 10 月 30 日

行政院國家科學委員會補助專題研究計畫成果報告期中進度報告


Characterization of terahertz waveguide and

waveguide-based biosensing chip

計畫類別個別型計畫整合型計畫

計畫編號NSC 97-2218-E-006-013 執行期間 97 年 3 月 1 日至 98 年 7 月 31 日


共同主持人

計畫參與人員

碩士班研究生-兼任助理人員陳豪志

博士班研究生-兼任助理人員游博文

成果報告類型(依經費核定清單規定繳交)精簡報告完整報告

本成果報告包括以下應繳交之附件

赴國外出差或研習心得報告一份

赴大陸地區出差或研習心得報告一份

出席國際學術會議心得報告及發表之論文各一份

國際合作研究計畫國外研究報告書一份

處理方式除產學合作研究計畫提升產業技術及人才培育研究計畫

列管計畫及下列情形者外得立即公開查詢

涉及專利或其他智慧財產權一年二年後可公開查詢

執行單位成功大學光電科學與工程研究所

中華民國 98 年 10 月 30 日

1

行政院國家科學委員會專題研究計畫進度報告




計畫編號NSC 97-2218-E-006-013

執行期限97 年3 月1 日至98 年7 月31 日

主持人呂佳諭

執行機構及單位名稱成功大學光電科學與工程研究所

E-mail jayumailnckuedutw

一中文摘要

兆赫波是指頻率在 01~10THz 範圍內的電磁波近來由於該頻段的產生和偵測技術上的進

步使的各國給予極大的關注形成一股研究熱潮本研究主要目標是積極投入創新研發低

損耗可色散控制高耦合效率的兆赫波光纖和波導並將此波導應用於微量分子偵測

發展各種小體積高靈敏度之兆赫波波導型感測器和光纖感測技術

原三年計畫目標是購買反波震盪器(BWO)作為兆赫波光源建立一寬頻可調之 CW兆赫波

頻譜和影像系統可以快速的掃描出待測樣品之頻譜以及同時獲得其相位來進行以上的

研究和發展兆赫波光纖光譜偵測技術原三年計劃之主要目標條列如下

1 建立一室溫操作寬頻可調和可快速掃瞄之 BWO‐based 穿透式和一反射式兆赫波

頻域頻譜系統

2 建立一 BWO-based 兆赫波影像系統可以反映出在 THz fiber 或 waveguide 截面

(cross-section)之兆赫波電磁場分布

3 發展各種低損耗可色散控制和高耦合率之次波長塑膠光纖

4 發展兆赫波光纖相關之光電子元件

5 完成不同結構之空心微結構光纖之兆赫波傳輸特性研究

6 開發兆赫波波導型微量分子偵測晶片和兆赫波光纖感測技術

由於計畫僅被核准一年半並且目標 1 和 2 的經費被全部刪除因此已將該目標於計畫中

排除為達成上述其它目的我們跟新竹工研院量測中心合作利用其超快雷射激發之兆

赫波頻譜系統已完成下列工作項目 1 完成次波長塑膠光纖之色散特性研究

2 完成利用消逝波偵測之次波長塑膠光纖感測器用以偵測微量分子

2

關鍵詞兆赫波次毫米波兆赫波光纖光纖感測器

Abstract

Terahertz (THz) electromagnetic waves lie between microwave and infrared with spectral range form 03THz to 10THz which is also called it ldquoT-rayrdquo Recent years much attention has been paid on THz and a fast development on THz science and technology has been achieved The aims of this research are development THz fibers and waveguides with low loss low dispersion and high free-space directed coupling efficiency capabilities as well as development of various kinds of high sensitive THz waveguide-based biosensors and THz fiber sensing technology for minute biomolecular detection In the original three-year program we plan to purchase a backward wave oscillator (BWO) for construction of a BWO based widely-tunable CW THz spectrometer and imaging system The BWO-based spectroscopic system could both acquire the transmission spectrum and phase of sample for investigation of waveguide dispersion of THz subwavelength fiber and development fiber sensing technique The specific aims of the research program are 1 To establish a room temperature widely-tunable and fast-scan BWO based transmittive

reflective THz frequency-domain spectrometer 2 To establish a BWO-based THz imaging system to acquire the cross-section of power

distribution at the output end of the THz fiber 3 To develop various low loss and dispersion controllable subwavelength plastic fibers with

high coupling efficiency 4 To develop various THz fiber based optoelectronic devices 5 To develop various hollow core microstructure fibers and investigate their THz transmission

properties 6 To develop THz waveguide based sensing chip and fiber sensing technique for minute

material detection Due to the fact that the funding related to the 1st and 2nd aim is not approved by the NSC this project will not pursue the development of a BWO based T-ray spectrometer and imaging system In this project we have accomplished the following results 1 We have successfully demonstrated a low loss and dispersion controllable subwavelength

plastic fibers with high coupling efficiency 2 We have successfully demonstrated a THz plastic wire based evanescent field sensor for high

sensitivity minute molecules detection

Keywords Terahertz wave sub-millimeter wave terahertz fiber fiber sensor

二計畫緣由與目的

目前國際關於兆赫波的研究主要集中在產生探測成像傳輸和頻譜等方面在傳輸

3

方面目前兆赫波仍依賴在自由空間中靠著面鏡間反射傳播但是兆赫波在大氣中的損耗

很大並且面鏡導波系統不但體積龐大也對某些應用例遙測通訊和內視鏡等造成限

制因此研發兆赫波波導或光纖就成為兆赫波傳輸的基礎也是兆赫波能否廣泛應用的關

鍵在成像和偵測方面許多生物大分子之豐富的轉動和振動能階落在兆赫頻段這些分

子共振吸收峰形成該分子的特徵辨識指紋因此利用這些指紋兆赫波得以非侵入式的且

不需外加染劑的探測各種物質而光纖或波導型元件具有小體積使用更具彈性方便可

遙測等優點若能結合兆赫波之無損傷探測物質能力和光纖元件之優點發展一個在臨床

上能準確快速且非侵入式的分辨出分子之技術在 DNA和基因檢測藥物篩選新藥測試

法醫鑑定和毒物辨識等方面將有很大的應用潛力本研究主要目標即積極投入創新研發低


發展小體積高靈敏度之兆赫波波導型感測器和光纖感測技術

本計劃第一部分將研究次波長兆赫波塑膠光纖之色散行為將對不同材質線徑和長度

之次波長塑膠光纖分別分析它們對不同頻率的兆赫波之波導色散(waveguide dispersion)

和傳輸損耗並且找出其色散機制以及進而控制其色散

第二部份主要發展兆赫波波導型微量分子感測器主要是利用消逝波偵測之次波長塑膠光

纖感測器原計畫是購買反波震盪器(BWO)作為兆赫波光源建立一寬頻可調之 CW兆赫波


研究和發展兆赫波光纖光譜偵測技術由於這部分經費被刪因此我們和新竹工研院量測

中心合作利用其超快雷射建立一寬頻兆赫波頻譜系統以達成上述目的

三結果與討論

該計畫已完成下列工作項目

1 建立寬頻兆赫波時域頻譜儀

為了量測次波長塑膠光纖的傳輸特性我們首先建立量測工具-寬頻兆赫波時域頻譜

儀該頻譜儀需要超快雷射激發因此我們跟新竹工研院量測中心合作借用其雷射

將頻譜儀建構在量測中心其系統架構及操作原理簡述如下

Fig1 是用以量測次波長塑膠光纖之兆赫波時域解析光譜儀系統此系統是利用超短脈

衝雷射光來激發兆赫波的產生與偵測並利用時間延遲(time-dealy)的方式來解析出兆

赫波波形脈衝雷射光束被分成兩道光線一個由反射鏡導引至兆赫波產生原件(THz

Emitter)上來激發兆赫波輻射兆赫波再被拋物面鏡引導至偵測元件上另一道脈衝雷

射光由反射鏡導引至偵測元件上(THz Detector)使的兆赫波與脈衝雷射光可以同時在

偵測元件上並利用時間延遲的方式將兆赫波脈衝在偵測器上被解析出電壓或是電流訊

號其中捷波器(chopper)與鎖相放大器(lock-in amplier)可以將系統雜訊濾除並同時

提高兆赫波的訊噪比(SN ratio)整體系統目的為提高訊噪比與得到更寬頻域的兆赫

波目前此系統是利用低溫成長砷化鎵(LT-GaAs)製作之光導天線產生和偵測兆赫波

[1-2]

As shown in Fig1 the THz emitter was optically excited using a mode-locked Tisapphire

4

laser with a central wavelength of 800nm a pulse width of 100fs and a repetition rate of 82MHz The generated THz pulse was collected and directly coupled into the subwavelength plastic wire (SPW) using a pair of parabolic mirrors By means of direct optical coupling a SPW typically delivers over 60 of the THz energy (including the coupling loss and the propagation loss) along a 30cm-long wire with a THz transmission spectrum centered at the wavelength of 1mm (λ=1mm) THz waves on the SPW propagated to the output end of the plastic wire were collected and focused onto a photoconductive switch receiver using a PE lens (f=6cm) and a parabolic mirror From the optical time-delay between the THz pump and the probe beams we can obtain the time-domain waveform of the THz pulse propagated through an SPW and information on both the phase and amplitude of the transmitted THz pulse could also be thus extracted Typically the signal-to-noise-ratio of an SPW-based THz time-domain spectrometer exceeds 105

Fig1 Terahertz time-domain spectrometer for characterization of subwavelength plastic wire

2 次波長塑膠光纖之色散特性研究

The dispersion property of the SPW is experimentally and theoretically investigated via a transmission-type THz time-domain spectroscopy (THz-TDS) system Transmission spectroscopy indicated that the SPW exhibits low and controllable waveguide dispersions which can be tuned by changing the core diameter the core index and the cladding index of the wire This fact is consistent with theoretical predictions By measuring the variation in the waveguide dispersion of an SPW with various molecules deposited in the wire cladding region the demonstrated SPW-based THz time-domain spectrometer can identify two similar white powders These results imply that SPWs can potentially be applied in future THz communication and the sensing of minute molecules This part of results has been submitted to Applied Physics Letters [3] and reported in Photonic West 2009 [4] Please refer to appendix I

3 次波長塑膠光纖微量分子感測器

THz transmission via subwavelength plastic wire has been demonstrated in which more than

5

90 of the THz power is guided outside the wire core [5] Besides decreasing the THz propagation loss incurred by wire absorption the enhanced evanescent wave increases the overlapped interaction between sample and THz wave possibly increasing the sensitivity and decreasing required amounts of the sample placed around the plastic wire THz subwavelength plastic wire is characterized by its easy availability low loss low dispersion [6] and efficient coupling by quasi-optics [5] which is highly promising for biomedical imaging [7 8] remote sensing and biochip applications

We have demonstrated a highly sensitive detection method based on the evanescent wave of a terahertz subwavelength plastic wire for liquid sensing The enhanced evanescent wave sensitizes waveguide dispersion of wire to the refractive index of wire cladding Slightly varying the cladding index can significantly change waveguide dispersion The dispersion deviation of guided THz wave is evaluated and two liquids ie water and alcohol are easily distinguished between each other which is consistent with theoretical predictions A melamine alcohol solution with different concentrations is then identified successfully with a detection limit of 20ppm implying that detection of index variation is on the order of 001 The proposed sensing method is highly promising for food quality control illicit drugs or explosives detection as well as molecular dynamic characterization in living cell specimens This part of results has been published in Optics Express [4 9] Please refer to appendix II

四計畫成果自評

本計畫研究內容與原計畫相符預期目標大致達成我們已經完成了兆赫波次波長塑膠光

纖的色散特性研究結果顯示次波長兆赫波光纖不但具有極低損耗(lt001cm-1)並且其波導

色散可經由調整光纖之線徑和折射率來控制在選定的波段達成零色散實驗量測結果和

理論模擬有很好的吻合性該結果對未來兆赫波光纖通訊和非線性應用具有相當不錯的應

用潛力我們也利用次波長兆赫波塑膠光纖之波導色散對fiber cladding折射率相當敏感的特

性將此塑膠光纖應用於微量分子感測上經由分析波導色散之低峰值的改變量我們成

功地辨識出兩種外觀相近的白色粉末並符合理論推估該兆赫波光纖感測技術也應用於偵

測高損耗液體中的分子濃度成功分辨出不同低濃度的三聚氰胺在酒精中的溶解情形其

中最低濃度辨識能力可以到達20ppm相當於可以以分辨出001的折射率差異之物質利用

兆號波次波長光纖的消逝波來感測微量物質的技術可以廣泛運用在各種低劑量物質感測

上例如違禁毒品爆裂物或是動態性偵測分子在物理或是化學反應中的生成物情況因

本計畫所發表之文章如下

(1) Borwen You Tze-An Liu Jin-Long Peng Ci-Ling Pan Ja-Yu Lu ldquoSubwavelength Plastic Wire Terahertz Time-domain Spectroscopyrdquo submitted to Applied Physics Letters (Under review)

(2) Borwen You Tze-An Liu Jin-Long Peng Ci-Ling Pan and Ja-Yu Lu A terahertz plastic wire based evanescent field sensor for high sensitivity liquid detection Opt Express 17

6

20675-20683 (2009) (3) Borwen You Tze-An Liu Jin-Long Peng Ci-Ling Pan Ja-Yu Lurdquo Characterization of

Subwavelength Plastic Fiber Utilizing Terahertz Time-Domain Spectroscopyrdquo presented at the Photonics West 2009 San Jose California USA Jan 24-29 (2009) published as Proceedings of SPIE Vol 7215 72150B (2009)

(4) Borwen You Tze-An Liu Jin-Long Peng Ci-Ling Pan Ja-Yu Lurdquo Characterization of Subwavelength Terahertz Plastic Fiber Utilizing Terahertz Time-Domain Spectroscopyrdquo Optics and Photonics Taiwan 2008 Section Sat-S10 Taipei Taiwan(2008) (最佳學生論文

獎)

五參考資料

1 httpwwwdelmarphotonicscomPCA_webpdf 2 Jiangquan Zhang and D Grischkowsky OPTICS LETTERS July 15 2004 Vol 29 No 14

PP1617 3 Borwen You Tze-An Liu Jin-Long Peng Ci-Ling Pan Ja-Yu Lu ldquoSubwavelength Plastic

Wire Terahertz Time-domain Spectroscopyrdquo submitted to Applied Physics Letters (Under reviewed)

4 Borwen You Tze-An Liu Jin-Long Peng Ci-Ling Pan Ja-Yu Lurdquo Characterization of Subwavelength Plastic Fiber Utilizing Terahertz Time-Domain Spectroscopyrdquo presented at the Photonics West 2009 San Jose California USA Jan 24-29 (2009) published as Proceedings of SPIE Vol 7215 72150B (2009)

5 Li-Jin Chen Hung-Wen Chen Tzeng-Fu Kao Ja-Yu Lu and Chi-Kuang Sun ldquoLow-loss subwavelength plastic fiber for terahertz waveguidingrdquo Opt Lett 31 308-310 (2006)

6 A Dupuis J-F Allard D Morris K Stoeffler C Dubois and M Skorobogatiy ldquoFabrication and THz loss measurements of porous subwavelength fibers using a directional coupler methodrdquo Opt Express 17 8012-8028 (2009)

7 Ja-Yu Lu Chui-Min Chiu Chung-Chiu Kuo Chih-Hsien Lai Hung-Chung Chang Yuh-Jing Hwang Ci-Ling Pan and Chi-Kuang Sun rdquoTerahertz scanning imaging with a subwavelength plastic fiberrdquo Appl Phys Lett 92 084102 (2008)

8 Chui-Min Chiu Hung-Wen Chen Yu-Ru Huang Yuh-Jing Hwang Wen-Jeng Lee Hsin-Yi Huang and Chi-Kuang Sun ldquoAll-terahertz fiber-scanning near-field microscopyrdquo Opt Lett 34 1084-1086 (2009)

9 Borwen You Tze-An Liu Jin-Long Peng Ci-Ling Pan and Ja-Yu Lu A terahertz plastic wire based evanescent field sensor for high sensitivity liquid detection Opt Express 17 20675-20683 (2009)

7

Appendix I

Submitted to Applied Physics Letters

Subwavelength Plastic Wire Terahertz Time-domain Spectroscopy

Borwen You and Ja-Yu Lu a)

Institute of Electro-Optical Science and Engineering National Cheng Kung University 1

Ta-Hsueh Road Tainan 70101 Taiwan ROC

Tze-An Liu and Jin-Long Peng

Center for Measurement Standards Industrial Technology Research Institute 321 Section 2

Kuang Fu Road Hsinchu 30011 Taiwan ROC

Ci-Ling Pan

Department of Photonics and Institute of Electro-Optical Engineering National Chiao Tung

University 1001 University Road Hsinchu 30010 Taiwan ROC

a) Author to whom correspondence should be addressed electronic mail

jayumailnckuedutw

PACS 8440-x 0757-c 8780-y

8

Abstract

This work demonstrates the feasibility of a terahertz time-domain spectrometer based on a

subwavelength-diameter plastic wire (SPW) for sensing applications The dispersion property of

the SPW is experimentally and theoretically studied The SPW exhibits a low and controllable

waveguide dispersion which can be engineered by changing the core diameter the core index

and the cladding index of the wire Two white powders tryptophan and polyethylene deposited

on the bottom of the wire can be successfully distinguished based on the waveguide dispersion of

SPW The SPW would be a promising candidate for combination with biochips for sensing

minute molecules

9

Various terahertz (THz) waveguides have been developed for efficient transmission of

THz waves and successfully applied in numerous fields such as spectroscopy12 sensing34 and

near field imaging5 However the proposed waveguides either have low coupling efficiency or

high propagation loss and high dispersion subsequently shortening the THz propagation

distance and reducing the capability for detecting strongly absorbed materials Among the

merits of the simple THz subwavelength plastic wire (THz-SPW) include single mode

sustentation a high coupling efficiency a low propagation loss6 (on the order of 001cm-1) as

well as theoretically low dispersion in the transmission band7 THz-SPW has been successfully

adopted in directional couplers8 endoscopic imaging9 and microscopy10 To our knowledge

the dispersion feature of THz-SPW has not been experimentally measured or analyzed

Because the core has a low index of refraction the extended electric field of an evanescent

wave on a THz-SPW6 is enhanced much more than an optical nanowire11 causing THz waves

on the SPW to interfere easily with the surrounding medium supporting remote sensing and the

detection of molecules in biochips or microfludic channels Dispersion shifts in optical

nanowires with thin dielectric coatings have been theoretically demonstrated12 revealing that

the waveguide dispersion of a weakly guiding fiber is very sensitive to the refraction index of

cladding In this letter the dispersion property of THz-SPW is experimentally and theoretically

investigated and the feasibility of integrating SPW with a THz time-domain spectroscopy

(THz-TDS) system for molecular sensing applications is demonstrated Transmission

spectroscopy indicated that the SPW exhibits low and controllable waveguide dispersions

which can be tuned by changing the core diameter the core index and the cladding index of

the wire This fact is consistent with theoretical predictions By measuring the variation in the

waveguide dispersion of an SPW with various molecules deposited in the wire cladding region

the demonstrated SPW-based THz time-domain spectrometer can identify two similar white

powders These results imply that SPWs can potentially be applied in future THz

communication and the sensing of minute molecules

10

In this study we used two SPWs whose cores were made of polyethylene (PE) and

polystyrene (PS) with refractive indices13 of 15 and 159 respectively and an air cladding

were adopted Dispersion in a THz-SPW is dominated by material dispersion and waveguide

dispersion The modal dispersion can be neglected because SPW is associated with the

single-mode wave-guiding Since the refractive indices of both PE and PS are almost constant

at THz frequencies14 the material dispersion in SPW can also be neglected The main

contribution of dispersion in a THz-SPW is waveguide dispersion In this experiment the

waveguide dispersion in an SPW was measured using a transmission-type THz time-domain

spectrometer which is schematically depicted in Fig 1 and consists of a pair of

LT-GaAs-based photoconductive antennas as the THz emitter and receiver The THz emitter

was optically excited using a mode-locked Tisapphire laser with a central wavelength of

800nm a pulse width of 100fs and a repetition rate of 82MHz The generated THz pulse was

collected and directly coupled into the SPW using a pair of parabolic mirrors By means of

direct optical coupling a 300μm-diameter PE wire delivers over 60 of the THz energy

(including the coupling loss and the propagation loss) along a 30cm-long wire with a THz

transmission spectrum centered at the wavelength of 1mm (λ=1mm) To measure the THz

waveguide dispersion and propagation loss in an SPW a standard cutback method was

employed with a fixed input coupling efficiency In the sensing experiment a sample holder

that was made of polypropylene (PP) on which was a 6mm-wide and 05mm-deep channel

filled with the test sample was placed on the bottom of a THz-SPW oriented parallel to the

length direction of a PP holder as presented in the inset in Fig1 Two PP holders with lengths

of 5mm and 8mm were adopted to determine the phase difference between the THz pulses

transmitted through the sample for dispersion calculation The SPW was slightly contact with

the sample to ensure overlap between the THz evanescent wave and the sample As

demonstrated two white powders with similar appearances tryptophan (T8941 L-Tryptophan

Sigma-Aldrich Inc) and polyethylene (434272 Polyethylene Sigma-Aldrich Inc) were

11

employed as test samples THz waves on the SPW transmitted through the powder sample and

propagated to the output end of the plastic wire were collected and focused onto a

photoconductive switch receiver using a PE lens (f=6cm) and a parabolic mirror From the

optical time-delay between the THz pump and the probe beams we can obtain the time-domain

waveform of the THz pulse propagated through an SPW and information on both the phase

and amplitude of the transmitted THz pulse could also be thus extracted Typically the

signal-to-noise-ratio of an SPW-based THz time-domain spectrometer exceeds 105

Maxwellrsquos equations are used to determine the theoretical group velocity Vg and the

waveguide dispersion Dwg of THz-SPW In Figs 2 (a) and (b) the theoretical group velocities

Vg (solid and dashed lines) of PS and PE wires approach to the speed of light (C) in a vacuum

at long wavelengths since a large fraction of the THz waves are propagated in air As the

wavelength becomes shorter more THz energy enters the wire core and thus declines Vg to a

value Cncore which is the group velocity of THz waves in the bulk material At a particular

wavelength a thinner SPW has a larger Vg because the THz energy is less confined as

displayed in Fig 2(a) In contrast the Vg of PS wire is less than that of PE wire as shown in

Fig 2(b) since the higher core index of the wire causes the THz wave to be strongly confined

within the wire core The theoretical waveguide dispersion Dwg (solid and dashed lines) of

SPW reaches a minimum value at the curve in Figs 2(c) and (d) and slowly approaches zero as

the wavelength increases For a weakly guiding wire waveguide a smaller diameter or a lower

core index causes the deep of the theoretical Dwg curve to shift to the short wavelengths as

shown in both Figs 2(c) and (d) The minimum of Dwg is more negative in a thinner SPW (PS

wire with a 300μm-diameter core) as shown in Fig 2(c) and becomes less negative as the core

index decreases (PE wire) as plotted in Fig 2(d)

By comparing the two measured THz waveforms that pass through SPWs of different

lengths we can obtain the THz effective index neff of SPW by the relation neff = 1+λφ(2πL)

12

where L and φ are the length and phase differences between two SPWs and λ is the THz

wavelength The measured group velocity11 Vg =-2πC(dβdλ)(λ2) and the measured

waveguide dispersion11 Dwg=d(1Vg)dλ can thus be calculated in an SPW where C is speed

of light in a vacuum and β is the effective propagation constant given by β=2πneffλ The

waveguide dispersion Dwg group velocity Vg propagation constant β and effective index of

SPW neff are all functions of THz wavelength In Figs 2(a) and (b) the measured

wavelength-dependent Vg of THz-SPWs follows a trend that is consistent with theory As

described above at a particular wavelength the measured group velocities in a weakly guiding

wire waveguide the 300μm-thick PS wire shown in Fig 2(a) and the 300μm-thick PE wire

shown in Fig 2(b) exceed that of 400μm-thick PS and 300μm-thick PS wires respectively

The measured wavelength-dependent Dwg of the THz-SPWs exhibits a trend that is consistent

with the theoretical result as shown in Figs 2(c) and (d) indicating the Dwg can be positive

zero or negative at a particular wavelength as determined by the chosen wire diameter and core

index Manipulating waveguide dispersion to control the properties of THz wave propagation is

important in many fields including communication and nonlinear optics

Given a geometry in which one portion of the THz evanescent field6 interacts with the

sample and the other portion leaks into the air as shown in the inset in Fig 1 the THz

evanescent wave resembles to be immersed in a new cladding with an effective refractive index

that differs from that of air The effective refractive index of the new cladding is determined by

both the air and the sample and is given by nclad=nairσ+nsample(1-σ) where σ is the power

percentage of the evanescent wave in the air The index of air nair equals 1 and nsample is the

refractive index of the sample in the THz frequency range In this experiment the average THz

refractive index of tryptophan and PE powder are 117 and 150 respectively1315 From the

geometric parameters of the wire and the PP channel that contained powders we can calculate

that 60 of the THz energy was in the air while 40 was in the powder From the above

relation the effective cladding indexes for PE and tryptophan powders are calculated as 12 and

13

1068 respectively Different cladding indices of the PS wire would differently affect the

propagation characteristics of the THz evanescent wave including effective index of refraction

and propagation constant thereby modifying the waveguide dispersion curve Figure 3(a) plots

the theoretically normalized waveguide dispersion of THz-SPWs with different cladding

indices and indicates the deep of the waveguide dispersion curve shifts toward the short

wavelength range and becomes less negative when an SPW turns into a weakly guiding

waveguide with a small index difference between the core and the cladding The trend plotted

in Fig 3(a) is similar to that in Fig 2(d) suggesting that the waveguide dispersion of SPW can

also be manipulated by changing the cladding index of the wire Figure 3(b) plots the

normalized measured wavelength-dependent waveguide dispersion curves of the THz pulse

transmitted through PE and tryptophan powder indicating that SPW immersed in PE powder

has a smaller negative Dwg at the deep of curve because the refractive index of the PE powder

is higher than that of tryptophan powder so the former less strongly confines THz waves that

pass through it which result is consistent with the simulated results plotted in Fig 3(a)

Notably a 17 variation of the measured waveguide dispersions between PE and tryptophan

powders is observed at the deepest point which finding is consistent with that estimated from

the aforementioned effective cladding indices The preliminary sensing result in Fig 3(b)

indicates that the THz-SPW can be used to identify two materials with similar appearances by

characterizing their measured waveguide dispersions The sensing scheme can potentially be

applied for monitoring the quality of food detection illicit drugs or explosives and

characterizing molecular dynamics in living cell specimens

The dispersion property of an SPW was experimentally and theoretically investigated using

transmission spectroscopy The SPW has a low and controllable waveguide dispersion which

can be engineered by changing the core diameter the core index and the cladding index of the

wire in a manner consistent with theoretical predictions Characterizing the waveguide

dispersion variations in SPW reveals that the demonstrated SPW-based THz time-domain

14

spectrometer can identify two similar white powders These results imply that SPW has

potential for use in communication applications and for combination with biochips or

micro-fluidic channels for sensing minute molecules

This work was supported by the Advanced Optoelectronic Technology Center National

Cheng Kung University under projects from the Ministry of Education and the National

Science Council (NSC 97-2218-E-006-013) of Taiwan The authors are grateful for the

preparation of plastic wires by the researcher JL Kuo in department of nanofiber materials

Industrial Technology Research Institute

15

References

1 M Walther M R Freeman and F A Hegmann Appl Phys Lett 87 261107 (2005)

2 N Laman S Sree Harsha D Grischkowsky and Joseph S Melinger Opt Express 16

4094 (2008)

3 T Hasek H Kurt D S Citrin and M Koch Appl Phys Lett 89 173508 (2006)

4 H Kurt and D S Citrin Appl Phys Lett 87 241119 (2005)

5 H-T Chen S Kraatz GC Cho and R Kersting Phys Rev Lett 93 267401 (2004)

6 L-J Chen H-W Chen T-F Kao J-Y Lu and C-K Sun Opt Lett 31 308 (2006)

7 A Dupuis J-F Allard D Morris K Stoeffler C Dubois and M Skorobogatiy Opt

Express 17 8012 (2009)

8 Hung-Wen Chen Chui-Min Chiu Chih-Hsien Lai Jeng-Liang Kuo Po-Jui Chiang

Yuh-Jing Hwang Hung-Chun Chang and Chi-Kuang Sun J Lightwave Technol 27 11

1489 (2008)

9 J-Y Lu C-M Chiu C-C Kuo C-H Lai H-C Chang Y-J Hwang C-L Pan and

C-K Sun Opt Express 16 2494 (2008)

10 Chui-Min Chiu Hung-Wen Chen Yu-Ru Huang Yuh-Jing Hwang Wen-Jeng Lee

16

Hsin-Yi Huang and Chi-Kuang Sun Opt Lett 34 1084 (2009)

11 L Tong J Lou and E Mazur Opt Express 12 1025 (2004)

12 J Y Lou L M Tong and Z Z Ye Opt Express 14 6993 (2006)

13 James W Lamb Int J Infrared Millimeter Waves 17 1997(1996)

14 R Piesiewicz C Jansen S Wietzke D Mittleman M Koch and T Kuumlrner Int J

Infrared Millimeter Waves 28 363 (2007)

15 B Yu F Zeng Y Yang Q Xing A Chechiny X Xin I Zeylikovich and R R Alfano

Biophys J 86 1649 (2004)

17

Figure 1 THz time-domain spectrometer based on subwavelength-diameter plastic wire (SPW) Inset shows THz pulse on an SPW propagated through powder materials in the PP channel

Figure 2 (a) Measured and theoretical group velocities Vg of the THz pulse on the PS wire with various core diameters At short wavelengths Vg approaches 063C for a PS wire (b) Measured and theoretical group velocities of THz pulse on 300μm-thick PS and PE wires (c) Measured and theoretical waveguide dispersions DWG of THz pulse on PS wire with various core diameters (d) Measured and theoretical waveguide dispersions of THz pulse on 300μm-thick PS and PE wires

18

Figure 3 (a) Theoretical normalized waveguide dispersions of 300μm-thick PS wire with various cladding indices (b) Measured (solid and dashed lines) and simulated (solid and open circles) waveguide dispersions of PS wire with PE and tryptophan powders in wire cladding regions

A terahertz plastic wire based evanescent field sensor for high sensitivity liquid detection Borwen You1 Tze-An Liu2 Jin-Long Peng2 Ci-Ling Pan3 and Ja-Yu Lu1

1 Institute of Electro-Optical Science and Engineering and Advanced Optoelectronic Technology Center National Cheng Kung University 1 University Road Tainan 70101 Taiwan ROC

2 Center for Measurement Standards Industrial Technology Research Institute 321 Section 2 Kuang Fu Road Hsinchu 30011 Taiwan ROC

3 Department of Photonics and Institute of Electro-Optical Engineering National Chiao Tung University 1001 University Road Hsinchu 30010 Taiwan ROC

jayumailnckuedutw

Abstract A highly sensitive detection method based on the evanescent wave of a terahertz subwavelength plastic wire was demonstrated for liquid sensing Terahertz power spreading outside the wire core makes the waveguide dispersion sensitive to the cladding index variation resulting in a considerable deviation of waveguide dispersion Two liquids with transparent appearances water and alcohol are easily distinguished based on the waveguide dispersion which is consistent with theoretical predictions A melamine alcohol solution with various concentrations is identified successfully and the detection limit is up to 20ppm ie equivalent to the index variation on the order of 001 copy2009 Optical Society of America OCIS codes (0602370) Fiber optics sensors (1306010) Sensors (2307370) Waveguides (3006495) Spectroscopy terahertz

References and links 1 L Cheng H Shinichiro A Dobroiu C Otani K Kawase T Miyazawa and Y Ogawa ldquoTerahertz-wave

absorption in liquids measured using the evanescent field of a silicon waveguiderdquo Appl Phys Lett 92(18) 181104 (2008)

2 M Walther M R Freeman and F A Hegmann ldquoMetal-wire terahertz time-domain spectroscopyrdquo Appl Phys Lett 87(26) 261107 (2005)

3 Y Sun X Xia H Feng H Yang C Gu and L Wang ldquoModulated terahertz responses of split ring resonators by nanometer thick liquid layersrdquo Appl Phys Lett 92(22) 221101 (2008)

4 A Ibraheem I Al-Naib C Jansen and M Koch ldquoThin-film sensing with planar asymmetric metamaterial resonatorsrdquo Appl Phys Lett 93 083507 (2008)

5 J F OrsquoHara R Singh I Brener E Smirnova J Han A J Taylor and W Zhang ldquoThin-film sensing with planar terahertz metamaterials sensitivity and limitationsrdquo Opt Express 16(3) 1786ndash1795 (2008)

6 H Kur ldquoCoupled-resonator optical waveguides for biochemical sensing of nanoliter volumes of analyte in the terahertz regionrdquo Appl Phys Lett 87(24) 241119 (2005)

7 F Miyamaru S Hayashi C Otani K Kawase Y Ogawa H Yoshida and E Kato ldquoTerahertz surface-wave resonant sensor with a metal hole arrayrdquo Opt Lett 31(8) 1118ndash1120 (2006)

8 H Yoshida Y Ogawa Y Kawai S Hayashi A Hayashi C Otani E Kato F Miyamaru and K Kawase ldquoTerahertz sensing method for protein detection using a thin metallic meshrdquo Appl Phys Lett 91(25) 253901 (2007)

9 S Yoshida E Kato K Suizu Y Nakagomi Y Ogawa and K Kawase ldquoTerahertz sensing of thin poly(ethylene terephthalate) film thickness using a metallic meshrdquo Appl Phys Express 2 012301 (2009)

10 M Nagel P Haring Bolivar M Brucherseifer H Kurz A Bosserhoff and R Buumlttner ldquoIntegrated THz technology for label-free genetic diagnosticsrdquo Appl Phys Lett 80(1) 154ndash156 (2002)

11 A Chakraborty and N Guchhait ldquoInclusion complex of charge transfer probe 4-amino-3-methyl benzoic acid methyl ester (AMBME) with b-CD in aqueous and non-aqueous medium medium dependent stoichiometry of the complex and orientation of probe molecule inside b-CD nanocavityrdquo J Incl Phenom Macrocycl Chem 62(1-2) 91ndash97 (2008)

12 N A Mortensen S Xiao and J Pedersen ldquoLiquid-infiltrated photonic crystals enhanced light-matter interactions for lab-on-a-chip applicationsrdquo Microfluid Nanofluid 4(1-2) 117ndash127 (2008)

13 L-J Chen H-W Chen T-F Kao J-Y Lu and C-K Sun ldquoLow-loss subwavelength plastic fiber for terahertz waveguidingrdquo Opt Lett 31(3) 308ndash310 (2006)

117682 - $1500 USD Received 24 Sep 2009 revised 23 Oct 2009 accepted 23 Oct 2009 published 27 Oct 2009

(C) 2009 OSA 9 November 2009 Vol 17 No 23 OPTICS EXPRESS 20675

JaYu_Lu
文字方塊
Appendix II

14 A Dupuis J-F Allard D Morris K Stoeffler C Dubois and M Skorobogatiy ldquoFabrication and THz loss measurements of porous subwavelength fibers using a directional coupler methodrdquo Opt Express 17(10) 8012ndash8028 (2009)

15 J-Y Lu C-M Chiu C-C Kuo C-H Lai H-C Chang Y-J Hwang C-L Pan and C-K Sun ldquoTerahertz scanning imaging with a subwavelength plastic fiberrdquo Appl Phys Lett 92(8) 084102 (2008)

16 C-M Chiu H-W Chen Y-R Huang Y-J Hwang W-J Lee H-Y Huang and C-K Sun ldquoAll-terahertz fiber-scanning near-field microscopyrdquo Opt Lett 34(7) 1084ndash1086 (2009)

17 L Tong J Lou and E Mazur ldquoSingle-mode guiding properties of subwavelength-diameter silica and silicon wire waveguidesrdquo Opt Express 12(6) 1025ndash1035 (2004)

18 J W Lamb ldquoMiscellancous data on materials for millimetre and submillimetre opticsrdquo Int J Infrared Milli 17 1996ndash2034 (1996)

19 J Lou L Tong and Z Ye ldquoModeling of silica nanowires for optical sensingrdquo Opt Express 13(6) 2135ndash2140 (2005)

20 H-W Chen Y-T Li C-L Pan J-L Kuo J-Y Lu L-J Chen and C-K Sun ldquoInvestigation on spectral loss characteristics of subwavelength terahertz fibersrdquo Opt Lett 32(9) 1017ndash1019 (2007)

21 B Ferguson and X-C Zhang ldquoMaterials for terahertz science and technologyrdquo Nat Mater 1(1) 26ndash33 (2002) 22 H Kitahara T Yagi K Mano and M W Takeda ldquoDielectric characteristics of water solutions of ethanol in the

terahertz regionrdquo J Korean Phys Soc 46 82ndash85 (2005) 23 L Thrane R H Jacobsen P Uhd Jepsen and S R Keiding ldquoTHz reflection spectroscopy of liquid waterrdquo

Chem Phys Lett 240(4) 330ndash333 (1995) 24 B E A Saleh and M C Teich fundamentals of photonics (John Wiley amp Sons New York NY 1991) 25 J Lou L Tong and Z Ye ldquoDispersion shifts in optical nanowires with thin dielectric coatingsrdquo Opt Express

14(16) 6993ndash6998 (2006) 26 C-L Chen elements of optoelectronics and fiber optics chap8 (Times Mirror Higher Education Group Inc

company 1996) 27 A Sano Kawasaki T Kuroishi Chiba Y Miyazaki Machida S Yokoyama Yokohama K Matsuura ldquoEasily

soluble polyethylene powder for the preparation of fibers or films having high strength and high elastic modulusrdquo united states patent 4760120 (1988) httpwwwfreepatentsonlinecom4760120pdf

28 IARC Monographs on the Evaluation of Carcinogenic Risks to Humans ldquoSome chemicals that cause tumours of the kidney or urinary bladder in rodents and some other substancesrdquo httpmonographsiarcfrENGMonographsvol73indexphp

29 R E N Baozeng L I Chen Y U A N Xiaoliang and W A N G Fuan ldquoDetermination and correlation of melamine solubilityrdquo Chin J Chem Eng 54(7) 1001ndash1003 (2003)

1 Introduction

Minute material detection has received considerable interest in genomic engineering lab-on-a-chip and forensic medicine applications Noninvasive and label-free molecular detection is easily achieved based on terahertz (THz) fingerprint spectra because their absorption bands originating from molecular transitions between vibrational or rotational energy levels are located in the THz frequency range THz technology has been extensively adopted for minute material detection in the recent decade A related method measures the relative absorption or molecular characteristic absorption spectrum such as the silicon waveguide [1] and metal wire [2] However for increasing the sensitivity it requires several milligrams of powders or a high concentration solution [12] Another means of detecting a slight amount of materials is based on refractive index sensitive THz devices such as metamaterials [3ndash5] coupled-resonator optical waveguide [6] and metal hole arrays [7ndash9] By utilizing a thin film micro-strip line (TFMS) Nagel et al [10] detected the deposited DNA with femto-mol level sensitivity based on the THz resonant band shift of TFMS by varying the sample indexes A chip-based THz device with a high sensitivity is advantageous for integration with various biochips and planer arrays for multiplexing However the TFMS is restricted in noninvasive remote sensing due to the limited transmission length In addition the solvents of samples deposited on the micro-strip line waveguide should be evaporated in the process of manipulating samples and the changed surroundings would possibly modify the intrinsic properties of samples [11] The subwavelength plastic wire delivered the evanescent wave with low THz photon energy and allowed for non-invasive sensing without sample contact therefore it could reduce the restriction mention above In addition to its flexibility for remotely detecting a sample placed anywhere such a scheme allows easy integration with biochip or microfludic channels for molecular sensing [12]

THz transmission via subwavelength plastic wire has been demonstrated in which more than 90 of the THz power is guided outside the wire core [13] Besides decreasing the THz



propagation loss incurred by wire absorption the enhanced evanescent wave increases the overlapped interaction between sample and THz wave possibly increasing the sensitivity and decreasing required amounts of the sample placed around the plastic wire THz subwavelength plastic wire is characterized by its easy availability low loss low dispersion [14] and efficient coupling by quasi-optics [13] which is highly promising for biomedical imaging [1516] remote sensing and biochip applications

This work demonstrates the feasibility of an evanescent wave sensor based on the subwavelength plastic wire for liquid sensing The enhanced evanescent wave sensitizes waveguide dispersion of wire to the refractive index of wire cladding Slightly varying the cladding index can significantly change waveguide dispersion The dispersion deviation of guided THz wave is evaluated and two liquids ie water and alcohol are easily distinguished between each other which is consistent with theoretical predictions A melamine alcohol solution with different concentrations is then identified successfully with a detection limit of 20ppm implying that detection of index variation is on the order of 001 The proposed sensing method is highly promising for food quality control illicit drugs or explosives detection as well as molecular dynamic characterization in living cell specimens

2 Evanescent wave of THz subwavelength plastic wire

The THz subwavelength plastic wire used in this experiment has a circular cross-section an infinite air-cladding and a step-index profile [1317] The wire core is made of polystyrene (PS) in which the refractive index is 159 [18] Due to the thin core and low core index a large portion of THz power is transmitted in the air cladding [13] It also means the power distribution profile of the THz pulse propagating on the PS wire is wavelength dependent For instance the calculated fractional THz power in the air cladding for a 300μm-core-diameter-PS wire exceeds 70 when the wavelength exceeds 1mm as illustrated in Fig 1(a) This finding implies that the long-wavelength portion of the THz pulse extends further into the air than the short-wavelength as shown in the inset in Fig 1(a) The long-wavelength portion possesses an enhanced evanescent wave subsequently reducing the propagation loss [13] and allowing high sensitivity detection of a medium that surrounds the wire core [19] Using the vector Maxwellrsquos Eqs (17) the waveguide dispersion of guided THz pulse on a 300μm-core-diameter-PS wire was determined for various cladding indices Figure 1(b) shows the calculated wavelength-dependent waveguide dispersions of a THz subwavelength wire with various cladding indices where normalized with respect to the lowest minimum value ie the case of an air cladding such that the dispersion minimum of the cladding index of 100 curve is normalized to minus1 The dip of normalized waveguide dispersion (deep point of curve in Fig 1(b)) becomes less negative and shifts towards a short wavelength when the cladding index increases [17] The percentage variation of negative waveguide dispersion defined as ΔDWG is approximately proportional to the increasing cladding index For instance a PS wire is observed to have around 1- ΔDWG per 001-increase in the cladding index For the subwavelength THz wire sensor the deviation of dispersion dip is resulted from the evanescent THz wave transmitted along different specimens with various refractive indices The cladding index is changed owing to a certain volume of air in the cladding being replaced by the higher index test samples Based on the detection mechanism the sensitive scheme to detect refractive index is allowed to identify various specimens without broadband THz transmission which is necessary for detecting THz absorption spectrum of materials And hence the sensing performance would not be restricted by the deliverable bandwidth even though the transmitted bandwidth of THz subwavelength fiber is typically around 200GHz which is dependent on the wire length and core absorption loss [20] By implementing this concept into practice subwavelength THz wire is a promising alternative for the detection of minute index variations



3 Experimental setup and waveguide dispersion measurement

By using the THz time-domain spectroscopy (THz-TDS) [21] system the experiment attempted to evaluate and characterize the waveguide dispersion of PS wire with various media that surrounded the wire core The configuration in Fig 2(a) contains a mode-locked

Fig 1 (a) Fractional power in the air cladding for a 300μm-core-diameter-PS wire The inset shows the THz power distribution across the PS wire The black dash line indicates the radius of PS wire (150μm) and the blue dash dot line represents the full with of half maximum (FWHM) range of HE11 mode (b) Normalized waveguide dispersion of 300μm-core-diameter PS wire with various cladding indexes ranging from 100 to 107

Tisapphire laser with a center wavelength of 800nm 100fs-pulse duration and 100MHz-repetition rate a THz emitter as well as a THz detector The THz emitter and detector are both low-temperature-GaAs-based photoconductive antennas with a 5μm electrode gap The generated THz wave was coupled to a 300μm-core-diameter-PS wire by two off-axis parabolic mirrors collimated by a THz lens and focused on the THz photoconductive antenna for detection A 300μm-core-diameter-PS wire with length of 15cm is used for liquid sensing experiment After THz pulse propagated through a 15cm-long air-clad PS wire the measured signalnoise ratio (SNR) is around 104 The measured attenuation constant of a 300μm-core-diameter-PS wire is illustrated in Fig 2(b) and the minimum attenuation is as low as 001cmminus1 A sample holder made of polypropylene (PP) contained a 6mm-wide and 05mm-deep channel which was filled with the test sample A 10 μm thick polyethylene (PE) film was attached on the top of the PP holder to prevent evaporation of the liquid sample In the experiment alcohol and water were used as the liquid samples with distinct THz refractive indices 260 and 145 [2223] respectively at 09mm wavelength Two PP holders with different lengths ie 1mm and 3mm respectively were used to evaluate the waveguide dispersion in order to acquire the phase difference of THz pulse propagating along the PS wire and through the test samples The inset in Fig 2(a) illustrates one portion of the evanescent field interacting with the sample and the other portion of the field is leaking into the air Due to the high attenuation of liquid sample a specimen was placed beneath the PS wire with a separation distance D1 of around several hundred micrometers to sustain an adequate SNR (gt100) of THz wave while insuring a good overlap between THz evanescent wave and the specimen as shown in the inset in Fig 2(a) As the illustration of Fig 2(b) the attenuation of the THz wave propagated on a 300μm-core-diameter-PS wire across a 3mm-long liquid-filled PP holder is increased from 001 to 1cmminus1 in 09~11mm-wavelength range with the separation D1 of 043mm Even though the SNR is decreased from 104 to 100 it is sufficient in the work to acquire the phase information for sensing a small amount of liquids

In the study the phase difference for THz wave transmitted along the wire with and without liquid samples is described as follows

( ) ( )1 1 2 2sL airL sL airLϕ ϕ ϕ ϕ ϕΔ equiv minus minus minus (1)



where 1sLϕ and 1airLϕ represent the phases accumulated by the THz pulse that passed through a L1-long PP holder with and without a sample respectively Similarly 2sLϕ and 2airLϕ refer to the phases of THz pulse propagating through L2-long PP holder with the same depth and width as L1-long PP holder Notably according to Eq (1) the phase difference considered here is only contributed from the THz wave along the 1 2L Lminus -long PS wire with the sample in the cladding region The effective index of THz wave propagated on the wire and propagation constant β = 2π effn λ can be derived by substituting ϕΔ in Eq (2)

( )2 1

n 1 2 Leff L

λ ϕπ

sdotΔ= +

minus (2)

Fig 2 (a) Experimental setup for THz evanescent wave sensing by using a subwavelength plastic wire The inset illustrates the cross section of interaction between THz evanescent wave and the sample where D1 refers to the separation between wire and top surface of sample and D2 denotes the depth of the PP holder (b) The attenuation of THz pulse propagated on an air-clad PS wire (thick dash dot line) and on a PS wire across an alcohol-filled (thin solid line) and a water-filled (thick dash line) PP sample holders The core diameter of PS wire is 300μm

The measured waveguide dispersion can be straightforwardly calculated from Eqs (3) and (4) [24] in which Vg represents the THz group velocity along the PS wire with sample cladding Different samples in the cladding of PS wire influence the propagation features of THz wave such as the effective index and propagation constant thus shifting the wavelength-dependent waveguide dispersion curve as illustrated in Fig 1(b)

2

2 1CVg dd

πβλ

λ

= minus sdot (3)



1( )gd V

Dwg dλ

minus

= (4)

4 Sensing results and discussions

The geometrical configuration in the inset in Fig 2(a) illustrates one portion of THz evanescent field interacting with the samples and the other leaking into the air For the THz wave on the plastic wire this resembles a new cladding with an effective index as attributed to both the air and the sample which can be defined as follows

( ) 1Eff clad air samplen n nσ σ= sdot + sdot minus (5)

where σ denotes the fractional power of evanescent THz wave in the air and 1-σ is that in the sample The index of air airn equals 1 and samplen refers to the refractive index of test sample in THz frequency range

According to Eqs (6) and (7) the power percentage in the air σ could be estimated from the geometric parameters including the wire radius r distance D1 and channel depth D2 as shown in the inset in Fig 2(a)

21 360θσ = minus (6)

1 1

1 2

cos r D

r D Dθ minus ⎛ ⎞+= ⎜ ⎟+ +⎝ ⎠

(7)

In the liquid sensing experiment the estimated air percentage σ is approximately 68 for D1 of 043mm channel depth D2 of 05mm and wire radius r of 015mm The effective cladding index can be calculated based on Eq (5) from the refractive index of a liquid and the air percentage in the sensing condition Based on the estimated effective cladding index the theoretical waveguide dispersion of THz pulse along the PS wire transmitting through a liquid sample can thus be obtained based on Eqs (3) and (4) In the study the refractive indices of water and alcohol in THz are considered as 260 and 145 [2223] respectively at 09mm wavelength By incorporating 68-σ into Eq (5) the effective cladding indices are therefore 1144 and 1512 for alcohol and water respectively Figure 3(a) shows the simulated wavelength-dependent waveguide dispersion indicating a 58 variation of the dip of waveguide dispersion between alcohol and water Figure 3(b) shows the measured waveguide dispersion of THz pulse propagated on the 300μm-core-diameter-PS wire with a liquid sample in the cladding region The dispersion dips between water and alcohol liquids also have a 58-variation which corresponds to the theoretical prediction in Fig 3(a) However there is a discrepancy in terms of the wavelength position of the waveguide dispersion dips between theory and the measured result shown in Fig 3(a) and (b) which is more obviously for sensing of water It could possibly be resulted from the high index of water which is larger than the PS core index to make the dip shift to long wavelength range [25] Nevertheless it did not affect qualitative understanding and calculation of dip-variation of waveguide dispersion induced from different cladding index Notably the material dispersion of water and alcohol did not be taken into account in the calculated waveguide dispersion shown in Fig 3(a) For example the calculated material dispersion of water [26] is on the order of 10minus6 psKmnm at wavelength range of 08~11 mm although the refractive index of water is obviously changed from 25 to 28 at this range [23] Therefore the material dispersion of water is small enough compared with the measured waveguide dispersion of PS wire with a water cladding (~-20 psKmnm at dip shown in Fig 3(b)) and the neglect is reasonable Based on the variation of waveguide dispersion ΔDWG different samples can be easily distinguished such as the water and alcohol in the experiment According to Fig 1(b) waveguide dispersion variations ΔDWG of several percent can be detected when the effective



cladding index is increased by 002 This finding suggests that the THz plastic wire based evanescent sensor enables one to distinguish the slight variation of specimen concentration in solutions corresponding to cladding index variation based on the variation of the waveguide dispersion dip

According to our results a small amount of plastic powders polyethylene (PE) (434272 ultra-high molecular weight surface-modified polyethylene powder Sigma-Aldrich Inc) and melamine (Melamine Nippon Bacterial Test Co Ltd) with the grain size of several tens micrometers are mixed in alcohol solutions separately with various concentrations In general the pure PE cannot be dissolved in alcohol however the PE powders with high molecular weight and a modified polar surface would be slightly dissolved in polar liquids [27] In the alcohol solution melamine powders are slightly solute [28] and its solubility [29] could be larger than PE powders due to the polar molecular structure We stirred the melamine (PE) alcohol solution in a beaker uniformly for several minutes When turn off the stirrer we instantly transferred the solution into the PP sample holder by a micropipette before the un-dissolved powders settled to the bottom of the beaker

Fig 3 (a) Simulated waveguide dispersion of 300μm-core-diameter-PS wire with an alcohol-cladding and a water-cladding Notably ΔDWG in the graph represents the decreased percentage of waveguide dispersion dips (b) The measured waveguide dispersions for 300μm-core-diameter-PS wire with liquid claddings of water and alcohol

The prepared melamine and PE alcohol solutions are with different concentrations 20~100ppm (part per million ie one milligram-powder per one liter of alcohol in this case) and the waveguide dispersion of THz pulse was measured by THz-TDS system Figures 4 (a) and (b) display the measured waveguide dispersions of THz pulse traveling on the 300μm-core-diameter-PS wire with melamine and PE alcohol solutions in the cladding region and the concentrations range from 0ppm to 100ppm Notably variations of waveguide dispersion dips are observed in Fig 4(a) while increasing the melamine concentration from 20ppm to 80ppm in alcohol solutions However the apparent deviation of waveguide dispersion dips from the PE-alcohol solution observed only when the PE concentration is altered from 20ppm to 40ppm Because the effective cladding index of PS wire is changed with the solute concentration in alcohol the waveguide dispersion of THz evanescent wave is modified and correlates with the theoretical prediction shown in Fig 1(b) In Figs 4(a) the percentage of variation of waveguide dispersion in relation to pure alcohol ΔDWG is approximately proportional to the increased concentration of melamine powder in the alcohol solution Additionally the rising of the waveguide dispersion dips apparently ceases even when more powders are mixed in the alcohol due to the saturation of alcohol ie 80ppm and 40ppm for melamine and PE powders respectively At the saturation excess situation the un-dissolved powders will be suspended in the solution However the material dispersion of the suspended grains in the alcohol solution could be neglected compared with the measured waveguide dispersion (with the dip value ranged from minus40 to minus60 psKmnm in Fig 4(a)) because the analysis of material dispersion in THz-TDS for PE and melamine bulks reveals that the



intrinsic dispersions (~10minus4 psKmnm) are negligible as shown in Fig 4(c) Additionally the extremely small amount of the suspended grains (~several tens ppm in this experiment) in the alcohol solution are difficult to modify the overall index of alcohol solution This is because the samplen in Eq (5) could be approximated to (1 ) solution grainn nρ ρminus + where ρ denotes the concentration of suspended grain on the order of 10minus6 and thus the effective cladding index is almost the same as the saturation case In the saturation excess condition the waveguide dispersion induced by the suspended powders is so small that it almost cannot affect the measured waveguide dispersion curve from the dissolved solute For example when PE powder concentration exceeds 40ppm as shown in Fig 4(b) the waveguide dispersion curve does not change indicating no matter the material dispersion or waveguide dispersion contributed from the suspended grains in the alcohol solution could not affect the measured waveguide dispersion Therefore the deviation of the measured waveguide dispersion is attributed to the dissolved materials in the alcohol solution

Fig 4 (a) Normalized waveguide dispersions for various mixed melamine concentrations in alcohol (b) Normalized waveguide dispersions for various mixed PE powder concentrations in alcohol (c) Material dispersion of melamine and PE bulk materials (d) Linear relation of effective cladding index and the dip-variation of waveguide dispersion derived from the melamine powder mixed in an alcohol solution at concentration of 20ppm to 80ppm The effective cladding indices for different concentrations are referred to the waveguide dispersion dips located in the wavelength range of 093~094mm

Closely examining Figs 4(a) and (b) reveals that the same mixed powder concentrations 40ppm of melamine and PE induce 21- and 18- ΔDWG respectively This finding suggests that an alcohol solution can dissolve more melamine powder than the PE powder Such an observation is reasonable since the polar molecular structure of melamine has a higher dissolution in the polar liquid alcohol compared with the non-polar molecular structure of PE powder Figure 4(d) shows the linear relation between the measured ΔDWG and effective cladding index for the melamine alcohol solution in which the solid line denotes the linear fit by polynomial The +minus1 error bars of the measured ΔDWG at wavelength range of 093~094mm are also added in Fig 4(d) which is induced from the measurement variations



of phase difference in THz-TDS system Based on the polynomial equation in Fig 4(d) the effective cladding index can be estimated from any known measured ΔDWG The polynomial equation is accurate to the second terms corresponding to two decimal places of effective cladding index THz refractive indices of the samples can thus be calculated from Eq (5) For example 58-ΔDWG of pure water observed in Fig 3(b) is applied in the fitting curve and the calculated refractive index of water is 266 which is around 2-deviation compared with the standard water index of 260 [22] at 09mm-wavelength Incorporation of +minus1 deviation of ΔDWG in water index calculation the calculated refractive index of water is ranged from 265 to 267 It indicates that the deviation of the calculated specimen index which is induced from the error (+minus1) in the measured waveguide dispersion is within 3 compared with its standard For the sensing results of melamine alcohol solution the effective cladding index of alcohol is increased with the solute concentration from 1144 to 1290 (40ppm) 1322 (60ppm) and 1368 (80ppm) Moreover according to Eq (5) the respective indices of melamine alcohol solution can be derived as 191 200 and 215 which are all larger than the original index of pure alcohol 145 This finding suggests that evanescent wave sensing based on subwavelength THz plastic wire provides adequately high sensitivity and reliability to identify minute index variation and the sensitivity can reach the order of 001

5 Conclusions

A noninvasive and label-free THz evanescent wave sensing based on subwavelength plastic wire has been demonstrated for liquid detection The enhanced evanescent wave causes considerable variation of waveguide dispersion when the cladding index change Additionally the dispersion deviation of guided THz wave is measured and two liquids with transparent appearances water and alcohol are easily distinguished which is consistent with theoretical predictions Based on the measured variation of waveguide dispersion dip various concentrations of melamine alcohol solution are successfully identified Moreover the detection limit is on the order of 20ppm corresponding to 001 index variation in cladding The THz subwavelength plastic wire based evanescent wave sensor is highly promising for use in various minute material detections such as illicit drugs or explosives as well as molecular dynamic detection such as to monitor the product generation rate in the chemical or physical reaction

Acknowledgment

This work was supported by the Advanced Optoelectronic Technology Center National Cheng Kung University under projects from the Ministry of Education and the National Science Council (NSC 97-2218-E-006-013 and NSC 98-2221-E-006-014-MY2) of Taiwan The authors are grateful for the preparation of plastic wires by the researcher JL Kuo in department of nanofiber materials Industrial Technology Research Institute



出席國際學術會議心得報告

計畫編號 97-2218-E-006-013

計畫名稱兆赫波波導及波導型感測器之特性研究

出國人員姓名

服務機關及職稱呂佳諭助理教授國立成功大學光電工程研究所

會議時間地點西元 2008 年 5 月 4 日至 5 月 9 日

San Jose Convention Center San Jose California USA

會議名稱 Conference on Lasers and Electro-Optics (CLEO)Quantum Electronics and Laser Science Conference (QELS) Conference on Photonic Application Systems and Technologies (PhAST)

發表論文題目 THz interferometric imaging using subwavelength plastic fiber based THz endoscopes

一參加會議經過

2008 年 Conference on Lasers and Electro-Optics (CLEO)仍循慣例在五月於 San Jose

Convention Center 舉辦由 Optical Society of America (OSA)IEEE Lasers and Electro Optics

Society (LEOS)及 American Physical Society (APS)共同主辦聯合主辦的 CLEO2008 可說是全

世界最重要的光電會議之一這是光電科學中對投稿文章篩選率最高的會議以今年來說總

共投稿了超過 2000 篇文章最後只有約一半的文章被接受能在會議中發表除了美國本土的研

究發表也有超過 20的文章是來自於全球其他地區的說明了這個國際性會議中成員的廣泛

性其中包含了許許多多的研究發表從最基本的物理突破到系統整合以至於產品的完成都

是經由挑選全球中最具創新突破最富經濟價值的研究成果來呈現在本次大會裡這次為期 6 天

的行程中(54~59)來自世界各地的光電界人士聚集於此發表研究成果數量多至每天需有十

一個平行處理的口頭報告會議廳(CLEO 八個QELS 二個JOINT 一個)和其中幾天有穿插

PhAST section這是和業界較為相關的光電元件最新發展報告內容之豐富可見一斑會議內

容的安排非常的多樣化主題橫跨雷射科技照明生醫光通信與物理研究相當廣泛

在口頭報告的議程中除了一般十五分鐘的投稿論文外尚穿插有針對各領域之引導入門式的

教學性演講 (Tutorial talk)並邀請當今各領域內最具權威的研究人員與會發表成果 (Invited

talk)由於議程的限制未能以口頭形式發表之論文則以壁報展覽之方式進行有興趣者可在

展覽時間內與壁報作者討論以玆以了解其內容會議並邀請許多具前瞻性的知名光電公司與會

展覽除了在會場展示公司所發展出的最新科技產品亦提供與會人員一個極佳的環境與廠商

交涉欲購買的產品並對廠商提出產品使用上的建議

JaYu_Lu
文字方塊
Appendix III

另外今年會議有三個 Plenary Session首先由佛羅里達大學的 David Reitze 介紹利用雷

射干涉儀觀察重力波來動態準確描繪出宇宙之時空曲面其準確度可達到 10-18米重力波

的發現和偵測在太空物理學上打開了一個新的觀察宇宙的窗口其次是由荷蘭的奈米光子

中心的領導人 Dr Albert Polman 介紹最近光電領域的熱門研究Plasmonics他介紹了最近幾

年如何在金屬薄膜上產生收集和控制表面電漿子(surface plasmons)也展示了利用微奈米粒

子做成陣列和奈米共振腔奈米共振腔能夠把光侷限在奈米尺度裡最後是由牛津大學的物

理系教授 Ian Walmsley 介紹量子光學他介紹了最新發現的光子量子態fock state這個奇

特的非古典物理可描述的光狀態在未來光子學領域提供了一新的展望今年的 CLEO 筆者自

己有一篇口頭報告題目是 THz interferometric imaging using subwavelength plastic fiber based THz endoscopes其中大家對最近才剛發展出來的次波長兆赫波光纖相當感興趣有相當多的

提問問題並且在會後也對此熱烈討論可見兆赫波光纖對目前兆赫波科技的發展的重要性

二與會心得

從前年開始每年 CLEO 會議已經逐漸再增加對兆赫波科技和應用的討論今年的 CLEO

對於我所感興趣的兆赫波科技其安排的 section 比例相當重幾乎每天都有一到兩間會議室從

早上會議開始到會議結束是專門在發表目前兆赫波的各種發展其內容涵蓋兆赫波各種產生

方式兆赫波偵測兆赫波近場光學兆赫波影像技術兆赫波在天文和生醫領域之應用

和各種兆赫波光電子元件之研發等可見兆赫波科技在全世界所受重視之程度今年 CLEO

大家所熱烈討論的話題一是和近場光學有關的 Plasmonics另一是一種新興人造材料

metamaterial 的設計和應用這兩個主題不只在可見光頻段受重視在兆赫波頻段也有不少實

現在兆赫波相關會議中特別將此二主題分別獨立出來討論筆者就這兩個議題所聽到的最

新發展簡述如下

Metamaterial 是一種人工週期結構材料其特性受控於結構單元幾何形狀及其空間分佈

有效介電常數和磁導率同時小於零在 metamaterial 中傳播的電磁場分量 EB 與波矢向量 k 滿

足ldquo左手定則電磁波的相速度與群速度方向相反從而呈現出許多奇異的物理光學特性

如反常 Doppler 效應反常 Cherenkov 效應完美透鏡效應負折射效應等目前對於 metamaterial

的研究主要集中於其奇異的透射行為方面如 Pendry 等提出週期排列開口諧振環（Split ring

resonators SRR）在其諧振頻率附近表現出有效磁導率為負週期排列金屬杆結構表現出類似于

高通濾波器行為即低頻時有效介電常數小於零Markos 等模擬了環厚度環開口環的幾何

尺寸等參數對週期排列 SRRS 的微波透射特性及諧振頻率的影響Shelby 等通過實驗觀察到微

波頻段電磁波通過 metamaterial 與空氣介面時發生ldquo負折射現象讓科學上要實現如電影哈

利波特中的隱形斗篷成為可能或製作超級透鏡讓電磁波通過有限孔徑的透鏡仍可完美聚

焦成一點目前科學家正在延伸此技術向更短的波長邁進另外Boston College 今年發表了利

用微影技術可以加工出完美的光吸收體的 metamaterial 結構不像是一般傳統的吸收體受限於

物理尺寸和天然的物理參數人造的 metamaterial 可用金屬加工成任意尺寸和任意調變其光學

參數如折射率或吸收係數等讓未來各種光學應用如光的收集和偵測成像等更具彈性兆

赫波頻段從去年底開始到目前為止也有許多利用 RLC 電路設計觀念設計出兆赫波頻段的

metamaterial 用於高效率的調變兆赫電磁波這些發表已經被刊在 PRLNature 和 Science 等著

名期刊上

表面等離子體是沿著導體表面傳播的波當改變金屬表面結構時表面等離子體激元

（Surface Plasmon polaritons SPPs）的性質色散關係激發模式耦合效應等都將產生重大

的變化 SPPs 是光波與可遷移的表面電荷（例如金屬中自由電子）之間相互作用產生的電

磁模- 這個電磁模有著大於同一頻率下光子在真空中或周邊介質中的波數因此通常情況

下這個電磁模不能被激發從導體表面輻射出去電磁場在垂直表面的兩個方向上均以

指數式衰減在一平坦金屬介電介面SPPs 沿著表面傳播由於金屬中歐姆熱效應它們將

逐漸耗盡能量只能傳播到有限的距離大約是微米或納米數量級只有當結構尺寸可以與

SPPs 傳播距離相比擬時SPPs 特性和效應才會顯露出來由於受早期製作電子元件的工藝水

準的限制加工不了微米納米尺寸的元件和回路所以 SPPs 顯露不出它的特性不為人們

所關注- 隨著工藝技術的長足進步現今製作特徵尺寸為微米和納米級的電子元件和回路

已不成問題了人們才重新點燃起研究 SPPs 的熱情通過 SPPs 與光場之間相互作用能夠

實現對光傳播的主動操控表面等離子體光子學（Plosmonics）已成為一門新興的學科它

的原理新穎效應以及機制的探究都極大地吸引研究者們的興趣金屬納米結構的表面等

離子體激發能夠產生非常特殊的光電性質例如可以產生很強的局域電場能夠使得拉曼散

射增強 1010 倍以上從而可以探測單個分子的拉曼散射表面等離子體光子學包含非常廣泛

的研究領域例如電場增強表面增強光譜增強的光透射表面等離子體納米波導增強

的光學力表面等離子體共振感測器表面增強的能量轉移及選擇性光吸收等等有研究員

通過利用表面等離子體增強光學力的方法人為地製造具有很強表面等離子體共振耦合的納米

金屬顆粒對來得到表面增強拉曼散射該研究成果已發表在 Nano Lettters 上SPPs 具有廣闊

的應用前景例如應用於製作各種 SPPs 元器件和回路製作納米波導表面等離子體光子

晶片耦合器調製器和開關應用於亞波長光學資料存儲新型光源突破衍射極限的超

分辨成像SPPs 納米光刻蝕術以及生物光學（作為感測器和探測器）等

三建議

CLEO 會議向來由 OSAAPS及 IEEELEOS 共同主辦跨物理及工程類之光學與光電先

進研究在此可看到最新的成果因該可以認為是國際上對重要之大型光電會議對於此重要會

議或許光電學門可以特案處理增加補助出國經費並積極增加本國之影響力雖然國內辦過

CLEOPacific Rim但在歐洲與美國主流研究者眼中他們根本就不會投稿參加 CLEOPacific

Rim原因是因為文章之接受度接近 100失去選擇性而使的大師級人物參加意願低落因此

參加 CLEO 還是應該放在比 CLEOEurope 與 CLEOPacific Rim 之上以增加台灣在主流研究者

中之地位

四攜回資料名稱及內容攜回 CLEO 之論文紙本和光碟各一份

THz interferometric imaging using subwavelength plastic

fiber based THz endoscopes

Ja-Yu Lu

Graduate Institute of Electro-Optical Science and Engineering National Cheng-Kung University Tainan 70101 Taiwan

Phone886-6-2757575 ext 65293 FAX886-6-2747995 E-mailjayumailnckuedutw

Chung-Chiu Kuo Chui-Min Chiu and Hung-Wen Chen

Department of Electrical Engineering and Graduate Institute of Photonics and Optoelectronics National Taiwan University Taipei 10617 Taiwan

Ci-Ling Pan

Graduate Institute of Electro-Optical Engineering National Chiao-Tung University Hsinchu 30056 Taiwan

Chi-Kuang Sun


Abstract We demonstrate a continuous-wave THz fiber-endoscopy by utilizing a low-loss THz

subwavelength plastic fiber The reconstructed 3D images not only reflect the depth variation the object

surface but also reveal the molecular distribution of samples

copy2008 Optical Society of America

OCIS codes (0602430) Fibers single-mode (2603090) Infrared

1 Introduction

Recently various kinds of THz waveguides or fibers have been developed for efficient transmission of THz

electromagnetic waves and have been used for THz biosensing applications However imaging applications are much

spared Many bio-molecules have their characteristic absorption fingerprint in the THz frequency range enabling

marker-free and direct recognition of molecular distribution Therefore if THz fiber scanning imaging could be realized

it will not only allow remote coupling to a bulky THz generation setup from the detected sample and allow flexible THz

wave guidance but will also greatly expand THz technology to intravital molecular imaging In this report we

demonstrate a CW THz fiber-based endoscope by using a subwavelength plastic fiber in which the sample is placed

behind the output of a THz subwavelength plastic fiber and the Fabry Perot interference is formed therein With a low

fractional power inside the fiber core the bending loss of the THz subwavelength fiber is acceptable to enable large

area scanning without seriously sacrificing the SNR of the acquired image [1] 3D THz reflective images with a high

lateral and subwavelength axial resolutions are acquired by moving the sample along the axial (z) direction and by 2D

scanning the output end of the subwavelength plastic fiber without any focusing medium By analyzing the

axial-position dependent THz signals backward collected by the subwavelength plastic fiber the THz reflection

amplitudes and phases on the sample surface can be successfully reconstructed

2 A subwavelength-plastic-fiber-based THz endoscope [2]

The adopted highly flexible THz subwavelength PE fibers was with a minimum attenuation constant typically on the

order of 001cm-1 [3] Our study indicated that within a scanning angle of plusmn2deg the fiber bending loss could be

negligible and thus enabling large-area scanning for imaging [1] The demonstrated THz fiber-endoscope which was

constructed with two THz subwavelength plastic fibers that formed a fiber-based directional coupler CW THz waves

from a Gunn oscillator module were coupled into and propagated along the input fiber By arranging part of these two

fibers in parallel and touched each other as a directional coupler a fraction of the input THz power will be coupled into

the imaging fiber through the overlapped region The coupled THz waves transmitted along the straight imaging fiber

were emitted from the fiber output end reflected by the sample under test and recoupled back along the same imaging

fiber back to a Golay cell for detection The measured THz spot size at the output of imaging fiber was 13 mm (at

320GHz with a 938μm wavelength) which revealed the fact that the subwavelength-fiber-based THz endoscope could

reach a near-diffraction-limited lateral resolution without focusing components By 2D lateral (x-y) scanning of the

imaging-fiber output end around a spatially-fixed sample a 2D THz fiber-endoscopic image could thus be obtained

The typical SNR of this imaging system is 12001 with a pixel dwelling time of 300 milliseconds

3 Experimental results

By moving the sample along the z direction versus the output end of the imaging fiber we observed that the measured

reflected THz power oscillated as shown in Fig 1(a) This is due to the interference of multiple reflective THz waves

between the sample surface and the output end of the imaging fiber With this phenomenon we analyzed the phase

information of the reflective THz waves which is useful for providing the depth information of the THz image We

acquire various 2D THz fiber-scanning reflective images by moving the imaging object at different z positions within

half of the THz wavelength to form a 3D data array Fig 1(b) and (c) show the 2D THz fiber-scanning reflective image

of a glass lens measured by positioning the lens tip at the fixed position z0 and z1 (labeled in Fig1(a)) respectively

Multiple rings are observed in the acquired 2D intensity images and these two images can be found to be out of phase

with each other which is the result of the Fabry Perot effect between the curved lens surface and the fiber output end

when z distance varies With the assumption of a smooth surface profile the depth information could be extracted by

analyzing the z-dependent data with a fixed x-y position Based on the correspondence between phase and distance at a

specific x-y position we were able to convert the extracted phases into heights and reconstruct the 3D surface profile

with an axial resolution much better than half of the wavelength Fig 1 (d) shows the reconstructed 3D THz image of

the glass lens in which colors represent different magnitudes of the extracted reflection oscillation amplitude The

reconstructed 3D surface profiles agree well with the lens maker formula indicating the accuracy of the phase

extraction program We also apply our developed fiber-endoscopy for biological THz imaging such as the diagnosis of

burned skin Fig 2(a) and (b) show the THz 2D images corresponding to the extracted amplitude and phase from the

burned porcine skin and (c) is the reconstructed 3D THz image of the burned porcine skin From Fig 2(c) the lateral

resolution of the system can be found to be around 1mm which was smaller than half of the beam radius The image

mechanism and detailed 3D image reconstructed algorithm will be presented in the conference

Fig 1 a The Golay cell measured THz reflection power by moving the glass lens along the z direction away from the imaging fiber tip and by

fixing the fiber-tip at the central point of the lens b and c The 2D fiber-scanning THz reflective images of the glass lens by positioning the lens at

the fixed z0 and z1 positions respectively as labeled in a d The reconstructed 3D THz image of the glass lens Colors represent different

magnitudes of the extracted reflection oscillation amplitude

Fig 2 THz 2D image corresponding to the a extracted amplitude and the b phase from the burned porcine skin The ring-shaped burned area can be

clearly identified c The reconstructed 3D THz image of the burned porcine skin Colors represent the extracted reflection oscillation amplitude

References

[1] J-Y Lu C-M Chiu C-Cu Kuo C-H Lai H-C Chang Y-J Hwang C-L Pan and C-K Sun ldquoTerahertz

scanning imaging with a subwavelength plastic fiberrdquo accepted by Appl Phys Lett (2007)

[2] J-Y Lu C-Cu Kuo C-M Chiu H-W Chen Y-J Hwang C-L Pan and C-K Sun ldquoTHz interferometric

imaging using subwavelength plastic fiber based THz endoscopesrdquo accepted by Opt Express (2007)

[3] H-W Chen Y-T Li J-L Kuo J-Y Lu L-J Chen C-L Pan and C-K Sun ldquoInvestigation on spectral loss

characteristics of subwavelength terahertz fibersrdquo Opt Lett 32 1017 (2007)


計畫編號 97-2218-E-006-013


出國人員姓名



































二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References







行政院國家科學委員會補助專題研究計畫成果報告期中進度報告




計畫類別個別型計畫整合型計畫

計畫編號NSC 97-2218-E-006-013 執行期間 97 年 3 月 1 日至 98 年 7 月 31 日


共同主持人

計畫參與人員

碩士班研究生-兼任助理人員陳豪志

博士班研究生-兼任助理人員游博文

成果報告類型(依經費核定清單規定繳交)精簡報告完整報告

本成果報告包括以下應繳交之附件

赴國外出差或研習心得報告一份

赴大陸地區出差或研習心得報告一份

出席國際學術會議心得報告及發表之論文各一份

國際合作研究計畫國外研究報告書一份

處理方式除產學合作研究計畫提升產業技術及人才培育研究計畫

列管計畫及下列情形者外得立即公開查詢

涉及專利或其他智慧財產權一年二年後可公開查詢

執行單位成功大學光電科學與工程研究所

中華民國 98 年 10 月 30 日

1





計畫編號NSC 97-2218-E-006-013


主持人呂佳諭



一中文摘要









頻域頻譜系統











2


Abstract












3




















三結果與討論















[1-2]


4







5


















6




獎)

五參考資料










7

Appendix I









Ci-Ling Pan




jayumailnckuedutw

PACS 8440-x 0757-c 8780-y

8

Abstract








minute molecules

9



























10



























11


























12



























13



























14









15

References



4094 (2008)






Express 17 8012 (2009)



1489 (2008)




16








Biophys J 86 1649 (2004)

17



18






jayumailnckuedutw


















JaYu_Lu
文字方塊
Appendix II
















1 Introduction




















( )2 1

n 1 2 Leff L

λ ϕπ

sdotΔ= +

minus (2)



2

2 1CVg dd

πβλ

λ

= minus sdot (3)



1( )gd V

Dwg dλ

minus

= (4)






21 360θσ = minus (6)

1 1

1 2

cos r D

r D Dθ minus ⎛ ⎞+= ⎜ ⎟+ +⎝ ⎠

(7)
















5 Conclusions


Acknowledgment





計畫編號 97-2218-E-006-013


出國人員姓名

























JaYu_Lu
文字方塊
Appendix III











二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References








計畫編號 97-2218-E-006-013


出國人員姓名



































二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References







1





計畫編號NSC 97-2218-E-006-013


主持人呂佳諭



一中文摘要









頻域頻譜系統











2


Abstract












3




















三結果與討論















[1-2]


4







5


















6




獎)

五參考資料










7

Appendix I









Ci-Ling Pan




jayumailnckuedutw

PACS 8440-x 0757-c 8780-y

8

Abstract








minute molecules

9



























10



























11


























12



























13



























14









15

References



4094 (2008)






Express 17 8012 (2009)



1489 (2008)




16








Biophys J 86 1649 (2004)

17



18






jayumailnckuedutw


















JaYu_Lu
文字方塊
Appendix II
















1 Introduction




















( )2 1

n 1 2 Leff L

λ ϕπ

sdotΔ= +

minus (2)



2

2 1CVg dd

πβλ

λ

= minus sdot (3)



1( )gd V

Dwg dλ

minus

= (4)






21 360θσ = minus (6)

1 1

1 2

cos r D

r D Dθ minus ⎛ ⎞+= ⎜ ⎟+ +⎝ ⎠

(7)
















5 Conclusions


Acknowledgment





計畫編號 97-2218-E-006-013


出國人員姓名

























JaYu_Lu
文字方塊
Appendix III











二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References








計畫編號 97-2218-E-006-013


出國人員姓名



































二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References







2


Abstract












3




















三結果與討論















[1-2]


4







5


















6




獎)

五參考資料










7

Appendix I









Ci-Ling Pan




jayumailnckuedutw

PACS 8440-x 0757-c 8780-y

8

Abstract








minute molecules

9



























10



























11


























12



























13



























14









15

References



4094 (2008)






Express 17 8012 (2009)



1489 (2008)




16








Biophys J 86 1649 (2004)

17



18






jayumailnckuedutw


















JaYu_Lu
文字方塊
Appendix II
















1 Introduction




















( )2 1

n 1 2 Leff L

λ ϕπ

sdotΔ= +

minus (2)



2

2 1CVg dd

πβλ

λ

= minus sdot (3)



1( )gd V

Dwg dλ

minus

= (4)






21 360θσ = minus (6)

1 1

1 2

cos r D

r D Dθ minus ⎛ ⎞+= ⎜ ⎟+ +⎝ ⎠

(7)
















5 Conclusions


Acknowledgment





計畫編號 97-2218-E-006-013


出國人員姓名

























JaYu_Lu
文字方塊
Appendix III











二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References








計畫編號 97-2218-E-006-013


出國人員姓名



































二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References







3




















三結果與討論















[1-2]


4







5


















6




獎)

五參考資料










7

Appendix I









Ci-Ling Pan




jayumailnckuedutw

PACS 8440-x 0757-c 8780-y

8

Abstract








minute molecules

9



























10



























11


























12



























13



























14









15

References



4094 (2008)






Express 17 8012 (2009)



1489 (2008)




16








Biophys J 86 1649 (2004)

17



18






jayumailnckuedutw


















JaYu_Lu
文字方塊
Appendix II
















1 Introduction




















( )2 1

n 1 2 Leff L

λ ϕπ

sdotΔ= +

minus (2)



2

2 1CVg dd

πβλ

λ

= minus sdot (3)



1( )gd V

Dwg dλ

minus

= (4)






21 360θσ = minus (6)

1 1

1 2

cos r D

r D Dθ minus ⎛ ⎞+= ⎜ ⎟+ +⎝ ⎠

(7)
















5 Conclusions


Acknowledgment





計畫編號 97-2218-E-006-013


出國人員姓名

























JaYu_Lu
文字方塊
Appendix III











二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References








計畫編號 97-2218-E-006-013


出國人員姓名



































二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References







4







5


















6




獎)

五參考資料










7

Appendix I









Ci-Ling Pan




jayumailnckuedutw

PACS 8440-x 0757-c 8780-y

8

Abstract








minute molecules

9



























10



























11


























12



























13



























14









15

References



4094 (2008)






Express 17 8012 (2009)



1489 (2008)




16








Biophys J 86 1649 (2004)

17



18






jayumailnckuedutw


















JaYu_Lu
文字方塊
Appendix II
















1 Introduction




















( )2 1

n 1 2 Leff L

λ ϕπ

sdotΔ= +

minus (2)



2

2 1CVg dd

πβλ

λ

= minus sdot (3)



1( )gd V

Dwg dλ

minus

= (4)






21 360θσ = minus (6)

1 1

1 2

cos r D

r D Dθ minus ⎛ ⎞+= ⎜ ⎟+ +⎝ ⎠

(7)
















5 Conclusions


Acknowledgment





計畫編號 97-2218-E-006-013


出國人員姓名

























JaYu_Lu
文字方塊
Appendix III











二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References








計畫編號 97-2218-E-006-013


出國人員姓名



































二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References







5


















6




獎)

五參考資料










7

Appendix I









Ci-Ling Pan




jayumailnckuedutw

PACS 8440-x 0757-c 8780-y

8

Abstract








minute molecules

9



























10



























11


























12



























13



























14









15

References



4094 (2008)






Express 17 8012 (2009)



1489 (2008)




16








Biophys J 86 1649 (2004)

17



18






jayumailnckuedutw


















JaYu_Lu
文字方塊
Appendix II
















1 Introduction




















( )2 1

n 1 2 Leff L

λ ϕπ

sdotΔ= +

minus (2)



2

2 1CVg dd

πβλ

λ

= minus sdot (3)



1( )gd V

Dwg dλ

minus

= (4)






21 360θσ = minus (6)

1 1

1 2

cos r D

r D Dθ minus ⎛ ⎞+= ⎜ ⎟+ +⎝ ⎠

(7)
















5 Conclusions


Acknowledgment





計畫編號 97-2218-E-006-013


出國人員姓名

























JaYu_Lu
文字方塊
Appendix III











二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References








計畫編號 97-2218-E-006-013


出國人員姓名



































二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References







6




獎)

五參考資料










7

Appendix I









Ci-Ling Pan




jayumailnckuedutw

PACS 8440-x 0757-c 8780-y

8

Abstract








minute molecules

9



























10



























11


























12



























13



























14









15

References



4094 (2008)






Express 17 8012 (2009)



1489 (2008)




16








Biophys J 86 1649 (2004)

17



18






jayumailnckuedutw


















JaYu_Lu
文字方塊
Appendix II
















1 Introduction




















( )2 1

n 1 2 Leff L

λ ϕπ

sdotΔ= +

minus (2)



2

2 1CVg dd

πβλ

λ

= minus sdot (3)



1( )gd V

Dwg dλ

minus

= (4)






21 360θσ = minus (6)

1 1

1 2

cos r D

r D Dθ minus ⎛ ⎞+= ⎜ ⎟+ +⎝ ⎠

(7)
















5 Conclusions


Acknowledgment





計畫編號 97-2218-E-006-013


出國人員姓名

























JaYu_Lu
文字方塊
Appendix III











二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References








計畫編號 97-2218-E-006-013


出國人員姓名



































二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References







7

Appendix I









Ci-Ling Pan




jayumailnckuedutw

PACS 8440-x 0757-c 8780-y

8

Abstract








minute molecules

9



























10



























11


























12



























13



























14









15

References



4094 (2008)






Express 17 8012 (2009)



1489 (2008)




16








Biophys J 86 1649 (2004)

17



18






jayumailnckuedutw


















JaYu_Lu
文字方塊
Appendix II
















1 Introduction




















( )2 1

n 1 2 Leff L

λ ϕπ

sdotΔ= +

minus (2)



2

2 1CVg dd

πβλ

λ

= minus sdot (3)



1( )gd V

Dwg dλ

minus

= (4)






21 360θσ = minus (6)

1 1

1 2

cos r D

r D Dθ minus ⎛ ⎞+= ⎜ ⎟+ +⎝ ⎠

(7)
















5 Conclusions


Acknowledgment





計畫編號 97-2218-E-006-013


出國人員姓名

























JaYu_Lu
文字方塊
Appendix III











二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References








計畫編號 97-2218-E-006-013


出國人員姓名



































二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References







8

Abstract








minute molecules

9



























10



























11


























12



























13



























14









15

References



4094 (2008)






Express 17 8012 (2009)



1489 (2008)




16








Biophys J 86 1649 (2004)

17



18






jayumailnckuedutw


















JaYu_Lu
文字方塊
Appendix II
















1 Introduction




















( )2 1

n 1 2 Leff L

λ ϕπ

sdotΔ= +

minus (2)



2

2 1CVg dd

πβλ

λ

= minus sdot (3)



1( )gd V

Dwg dλ

minus

= (4)






21 360θσ = minus (6)

1 1

1 2

cos r D

r D Dθ minus ⎛ ⎞+= ⎜ ⎟+ +⎝ ⎠

(7)
















5 Conclusions


Acknowledgment





計畫編號 97-2218-E-006-013


出國人員姓名

























JaYu_Lu
文字方塊
Appendix III











二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References








計畫編號 97-2218-E-006-013


出國人員姓名



































二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References







9



























10



























11


























12



























13



























14









15

References



4094 (2008)






Express 17 8012 (2009)



1489 (2008)




16








Biophys J 86 1649 (2004)

17



18






jayumailnckuedutw


















JaYu_Lu
文字方塊
Appendix II
















1 Introduction




















( )2 1

n 1 2 Leff L

λ ϕπ

sdotΔ= +

minus (2)



2

2 1CVg dd

πβλ

λ

= minus sdot (3)



1( )gd V

Dwg dλ

minus

= (4)






21 360θσ = minus (6)

1 1

1 2

cos r D

r D Dθ minus ⎛ ⎞+= ⎜ ⎟+ +⎝ ⎠

(7)
















5 Conclusions


Acknowledgment





計畫編號 97-2218-E-006-013


出國人員姓名

























JaYu_Lu
文字方塊
Appendix III











二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References








計畫編號 97-2218-E-006-013


出國人員姓名



































二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References







10



























11


























12



























13



























14









15

References



4094 (2008)






Express 17 8012 (2009)



1489 (2008)




16








Biophys J 86 1649 (2004)

17



18






jayumailnckuedutw


















JaYu_Lu
文字方塊
Appendix II
















1 Introduction




















( )2 1

n 1 2 Leff L

λ ϕπ

sdotΔ= +

minus (2)



2

2 1CVg dd

πβλ

λ

= minus sdot (3)



1( )gd V

Dwg dλ

minus

= (4)






21 360θσ = minus (6)

1 1

1 2

cos r D

r D Dθ minus ⎛ ⎞+= ⎜ ⎟+ +⎝ ⎠

(7)
















5 Conclusions


Acknowledgment





計畫編號 97-2218-E-006-013


出國人員姓名

























JaYu_Lu
文字方塊
Appendix III











二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References








計畫編號 97-2218-E-006-013


出國人員姓名



































二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References







11


























12



























13



























14









15

References



4094 (2008)






Express 17 8012 (2009)



1489 (2008)




16








Biophys J 86 1649 (2004)

17



18






jayumailnckuedutw


















JaYu_Lu
文字方塊
Appendix II
















1 Introduction




















( )2 1

n 1 2 Leff L

λ ϕπ

sdotΔ= +

minus (2)



2

2 1CVg dd

πβλ

λ

= minus sdot (3)



1( )gd V

Dwg dλ

minus

= (4)






21 360θσ = minus (6)

1 1

1 2

cos r D

r D Dθ minus ⎛ ⎞+= ⎜ ⎟+ +⎝ ⎠

(7)
















5 Conclusions


Acknowledgment





計畫編號 97-2218-E-006-013


出國人員姓名

























JaYu_Lu
文字方塊
Appendix III











二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References








計畫編號 97-2218-E-006-013


出國人員姓名



































二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References







12



























13



























14









15

References



4094 (2008)






Express 17 8012 (2009)



1489 (2008)




16








Biophys J 86 1649 (2004)

17



18






jayumailnckuedutw


















JaYu_Lu
文字方塊
Appendix II
















1 Introduction




















( )2 1

n 1 2 Leff L

λ ϕπ

sdotΔ= +

minus (2)



2

2 1CVg dd

πβλ

λ

= minus sdot (3)



1( )gd V

Dwg dλ

minus

= (4)






21 360θσ = minus (6)

1 1

1 2

cos r D

r D Dθ minus ⎛ ⎞+= ⎜ ⎟+ +⎝ ⎠

(7)
















5 Conclusions


Acknowledgment





計畫編號 97-2218-E-006-013


出國人員姓名

























JaYu_Lu
文字方塊
Appendix III











二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References








計畫編號 97-2218-E-006-013


出國人員姓名



































二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References







13



























14









15

References



4094 (2008)






Express 17 8012 (2009)



1489 (2008)




16








Biophys J 86 1649 (2004)

17



18






jayumailnckuedutw


















JaYu_Lu
文字方塊
Appendix II
















1 Introduction




















( )2 1

n 1 2 Leff L

λ ϕπ

sdotΔ= +

minus (2)



2

2 1CVg dd

πβλ

λ

= minus sdot (3)



1( )gd V

Dwg dλ

minus

= (4)






21 360θσ = minus (6)

1 1

1 2

cos r D

r D Dθ minus ⎛ ⎞+= ⎜ ⎟+ +⎝ ⎠

(7)
















5 Conclusions


Acknowledgment





計畫編號 97-2218-E-006-013


出國人員姓名

























JaYu_Lu
文字方塊
Appendix III











二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References








計畫編號 97-2218-E-006-013


出國人員姓名



































二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References







14









15

References



4094 (2008)






Express 17 8012 (2009)



1489 (2008)




16








Biophys J 86 1649 (2004)

17



18






jayumailnckuedutw


















JaYu_Lu
文字方塊
Appendix II
















1 Introduction




















( )2 1

n 1 2 Leff L

λ ϕπ

sdotΔ= +

minus (2)



2

2 1CVg dd

πβλ

λ

= minus sdot (3)



1( )gd V

Dwg dλ

minus

= (4)






21 360θσ = minus (6)

1 1

1 2

cos r D

r D Dθ minus ⎛ ⎞+= ⎜ ⎟+ +⎝ ⎠

(7)
















5 Conclusions


Acknowledgment





計畫編號 97-2218-E-006-013


出國人員姓名

























JaYu_Lu
文字方塊
Appendix III











二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References








計畫編號 97-2218-E-006-013


出國人員姓名



































二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References







15

References



4094 (2008)






Express 17 8012 (2009)



1489 (2008)




16








Biophys J 86 1649 (2004)

17



18






jayumailnckuedutw


















JaYu_Lu
文字方塊
Appendix II
















1 Introduction




















( )2 1

n 1 2 Leff L

λ ϕπ

sdotΔ= +

minus (2)



2

2 1CVg dd

πβλ

λ

= minus sdot (3)



1( )gd V

Dwg dλ

minus

= (4)






21 360θσ = minus (6)

1 1

1 2

cos r D

r D Dθ minus ⎛ ⎞+= ⎜ ⎟+ +⎝ ⎠

(7)
















5 Conclusions


Acknowledgment





計畫編號 97-2218-E-006-013


出國人員姓名

























JaYu_Lu
文字方塊
Appendix III











二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References








計畫編號 97-2218-E-006-013


出國人員姓名



































二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References







16








Biophys J 86 1649 (2004)

17



18






jayumailnckuedutw


















JaYu_Lu
文字方塊
Appendix II
















1 Introduction




















( )2 1

n 1 2 Leff L

λ ϕπ

sdotΔ= +

minus (2)



2

2 1CVg dd

πβλ

λ

= minus sdot (3)



1( )gd V

Dwg dλ

minus

= (4)






21 360θσ = minus (6)

1 1

1 2

cos r D

r D Dθ minus ⎛ ⎞+= ⎜ ⎟+ +⎝ ⎠

(7)
















5 Conclusions


Acknowledgment





計畫編號 97-2218-E-006-013


出國人員姓名

























JaYu_Lu
文字方塊
Appendix III











二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References








計畫編號 97-2218-E-006-013


出國人員姓名



































二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References







17



18






jayumailnckuedutw


















JaYu_Lu
文字方塊
Appendix II
















1 Introduction




















( )2 1

n 1 2 Leff L

λ ϕπ

sdotΔ= +

minus (2)



2

2 1CVg dd

πβλ

λ

= minus sdot (3)



1( )gd V

Dwg dλ

minus

= (4)






21 360θσ = minus (6)

1 1

1 2

cos r D

r D Dθ minus ⎛ ⎞+= ⎜ ⎟+ +⎝ ⎠

(7)
















5 Conclusions


Acknowledgment





計畫編號 97-2218-E-006-013


出國人員姓名

























JaYu_Lu
文字方塊
Appendix III











二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References








計畫編號 97-2218-E-006-013


出國人員姓名



































二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References







18






jayumailnckuedutw


















JaYu_Lu
文字方塊
Appendix II
















1 Introduction




















( )2 1

n 1 2 Leff L

λ ϕπ

sdotΔ= +

minus (2)



2

2 1CVg dd

πβλ

λ

= minus sdot (3)



1( )gd V

Dwg dλ

minus

= (4)






21 360θσ = minus (6)

1 1

1 2

cos r D

r D Dθ minus ⎛ ⎞+= ⎜ ⎟+ +⎝ ⎠

(7)
















5 Conclusions


Acknowledgment





計畫編號 97-2218-E-006-013


出國人員姓名

























JaYu_Lu
文字方塊
Appendix III











二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References








計畫編號 97-2218-E-006-013


出國人員姓名



































二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References











jayumailnckuedutw


















JaYu_Lu
文字方塊
Appendix II
















1 Introduction




















( )2 1

n 1 2 Leff L

λ ϕπ

sdotΔ= +

minus (2)



2

2 1CVg dd

πβλ

λ

= minus sdot (3)



1( )gd V

Dwg dλ

minus

= (4)






21 360θσ = minus (6)

1 1

1 2

cos r D

r D Dθ minus ⎛ ⎞+= ⎜ ⎟+ +⎝ ⎠

(7)
















5 Conclusions


Acknowledgment





計畫編號 97-2218-E-006-013


出國人員姓名

























JaYu_Lu
文字方塊
Appendix III











二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References








計畫編號 97-2218-E-006-013


出國人員姓名



































二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References






















1 Introduction




















( )2 1

n 1 2 Leff L

λ ϕπ

sdotΔ= +

minus (2)



2

2 1CVg dd

πβλ

λ

= minus sdot (3)



1( )gd V

Dwg dλ

minus

= (4)






21 360θσ = minus (6)

1 1

1 2

cos r D

r D Dθ minus ⎛ ⎞+= ⎜ ⎟+ +⎝ ⎠

(7)
















5 Conclusions


Acknowledgment





計畫編號 97-2218-E-006-013


出國人員姓名

























JaYu_Lu
文字方塊
Appendix III











二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References








計畫編號 97-2218-E-006-013


出國人員姓名



































二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References






















( )2 1

n 1 2 Leff L

λ ϕπ

sdotΔ= +

minus (2)



2

2 1CVg dd

πβλ

λ

= minus sdot (3)



1( )gd V

Dwg dλ

minus

= (4)






21 360θσ = minus (6)

1 1

1 2

cos r D

r D Dθ minus ⎛ ⎞+= ⎜ ⎟+ +⎝ ⎠

(7)
















5 Conclusions


Acknowledgment





計畫編號 97-2218-E-006-013


出國人員姓名

























JaYu_Lu
文字方塊
Appendix III











二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References








計畫編號 97-2218-E-006-013


出國人員姓名



































二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References
















( )2 1

n 1 2 Leff L

λ ϕπ

sdotΔ= +

minus (2)



2

2 1CVg dd

πβλ

λ

= minus sdot (3)



1( )gd V

Dwg dλ

minus

= (4)






21 360θσ = minus (6)

1 1

1 2

cos r D

r D Dθ minus ⎛ ⎞+= ⎜ ⎟+ +⎝ ⎠

(7)
















5 Conclusions


Acknowledgment





計畫編號 97-2218-E-006-013


出國人員姓名

























JaYu_Lu
文字方塊
Appendix III











二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References








計畫編號 97-2218-E-006-013


出國人員姓名



































二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References








( )2 1

n 1 2 Leff L

λ ϕπ

sdotΔ= +

minus (2)



2

2 1CVg dd

πβλ

λ

= minus sdot (3)



1( )gd V

Dwg dλ

minus

= (4)






21 360θσ = minus (6)

1 1

1 2

cos r D

r D Dθ minus ⎛ ⎞+= ⎜ ⎟+ +⎝ ⎠

(7)
















5 Conclusions


Acknowledgment





計畫編號 97-2218-E-006-013


出國人員姓名

























JaYu_Lu
文字方塊
Appendix III











二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References








計畫編號 97-2218-E-006-013


出國人員姓名



































二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References







1( )gd V

Dwg dλ

minus

= (4)






21 360θσ = minus (6)

1 1

1 2

cos r D

r D Dθ minus ⎛ ⎞+= ⎜ ⎟+ +⎝ ⎠

(7)
















5 Conclusions


Acknowledgment





計畫編號 97-2218-E-006-013


出國人員姓名

























JaYu_Lu
文字方塊
Appendix III











二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References








計畫編號 97-2218-E-006-013


出國人員姓名



































二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References



















5 Conclusions


Acknowledgment





計畫編號 97-2218-E-006-013


出國人員姓名

























JaYu_Lu
文字方塊
Appendix III











二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References








計畫編號 97-2218-E-006-013


出國人員姓名



































二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References













5 Conclusions


Acknowledgment





計畫編號 97-2218-E-006-013


出國人員姓名

























JaYu_Lu
文字方塊
Appendix III











二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References








計畫編號 97-2218-E-006-013


出國人員姓名



































二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References








5 Conclusions


Acknowledgment





計畫編號 97-2218-E-006-013


出國人員姓名

























JaYu_Lu
文字方塊
Appendix III











二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References








計畫編號 97-2218-E-006-013


出國人員姓名



































二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References








計畫編號 97-2218-E-006-013


出國人員姓名

























JaYu_Lu
文字方塊
Appendix III











二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References








計畫編號 97-2218-E-006-013


出國人員姓名



































二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References

















二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References








計畫編號 97-2218-E-006-013


出國人員姓名



































二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References













名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References








計畫編號 97-2218-E-006-013


出國人員姓名



































二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References









三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References








計畫編號 97-2218-E-006-013


出國人員姓名



































二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References









Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References








計畫編號 97-2218-E-006-013


出國人員姓名



































二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References















































References








計畫編號 97-2218-E-006-013


出國人員姓名



































二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References













References








計畫編號 97-2218-E-006-013


出國人員姓名



































二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References








計畫編號 97-2218-E-006-013


出國人員姓名



































二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References

















二與會心得


























名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References













名期刊上























三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References









三建議







中之地位




Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References









Ja-Yu Lu





Ci-Ling Pan


Chi-Kuang Sun







1 Introduction
























































References















































References













References







Documents

政院國家科學委員會專題研究計畫 成果報告ir.lib.ncku.edu.tw/bitstream/987654321/139069/1/兆赫波波導及波導型感測器之... · 關鍵詞：兆赫波、次毫米波、兆赫波光纖、光纖感測器。

政院國家科學委員會專題研究計畫成果報告ir.lib.ncku.edu.tw/bitstream/987654321/139069/1/兆赫波波導及波導型感測器之... · 關鍵詞：兆赫波、次毫米波、兆赫波光纖、光纖感測器。