Annual Report University of Dayton SPIE Chapter

Officers : Aziz Mahfoud, President Patrick Berry, Vice President Joseph Binford, Secretary Gurkan Peksoz, Treasurer

Guest Lecturers Prof. Vladislav Yakolev “Nonlinear Optical Interaction on a Nanoscale”, March 26, 2004.

Friday, March 26, 2004Science Center Room 119

3:00 P.M.For further information, please contact Trina Gonzalez at 229-2797.

Electro-Optics & Physics Seminar

Nonlinear optical interactions on a nanoscale

SPIE Series Lectures

Prof. Vladislav YakovlevDepartment of Physics

University of Wisconsin - Milwaukee

Optical methods are traditionally viewed as rather informative and simple tools to collect the information about materials. However, the fundamental diffraction limit established in 1873 by E. Abbe strictly defines the ultimate spatial resolution. The idea of cheating on diffraction using a tiny aperture and near-field optics was first suggested by E. Synge in 1928 and first experimentally realized by W. Denk in 1984. We employ nonlinear optical interactions to make a nanometer size light source and will discuss the opportunities of a novel approach for nanoscopic imaging. In my talk I will first describe novel sources of ultrashort laser pulses, which are inexpensive and easy to build and, in the same time, reliable and versatile. Rather than talking about the variety of nonlinear optical techniques, I will focus on the third-harmonic generation and will show how significant and non-trivial information can be obtained from a set of simple measurements. Finally, I will introduce a novel concept of multiplexed nanoscopic imaging and show our latest results towards achieving this goal.

Prof. Yakolev with members of the SPIE student chapter. From left to write, Aziz Mahfoud, president, Patrick Berry, vice-presidente, Cong Deng member.

3D-IMAGING OF ORIENTATIONAL STRUCTURES IN CHOLESTERIC LIQUID CRYSTALS AND THEIR ELECTRO-

OPTIC APPLICATIONS

SPIE Series Lectures

I.I. Smalyukh Chemical Physics Interdisciplinary Program and Liquid Crystal

Institute Kent State University

Kent, Ohio E-mail: smalyukh@lci.kent.edu

The director fields that specify average molecular orientation in liquid crystals (LCs) often form complex 3D patterns and are widely used in many optical applications. In the first part of the talk, we demonstrate how to image the 3D director fields using approach which we call the fluorescence confocal polarizing microscopy (FCPM) [1-3]. In the approach, we employ the property of liquid crystals to orient fluorescent dye molecules, dissolved in small quantities in the liquid crystal ‘host’. When the observation is performed in polarized light, the measured fluorescence signal is determined by the orientation of the molecules [1,3]. We use twisted nematic cells to control the polarization state of the probing light. The analysis of FCPM textures for different polarization states of excitation/fluorescence light reveals the orientation of molecules in the studied sample. We show that by using special dyes and probing light with well-controlled polarization state, the confocal microscopy can give an access not only to the 3D spatial positional patterns and concentrational distributions, but also to the 3D pattern of molecular orientation. Computer-simulated and experimental FCPM textures of these patterns closely match each other. We present the patterns of orientational order associated with static and dynamic processes, such as climb and glide of dislocations mediated by surface anchoring, electric field-induced transitions between different cholesteric textures, formation of hexagonal ordered structures of cholesteric bubbles, etc. Based on the FCPM studies and the theoretical analysis, we describe the important parameters (such as surface anchoring, elastic constants, etc.) of the CLC that allow us to obtain defect-free periodic cholesteric structures for electro-optical applications. In the second part of the talk, we then demonstrate the feasibility of using these structures for a variety of photonic and electro-optic applications. As an example, we use the hexagonal arrays of cholesteric bubbles for switchable two-dimensional diffraction gratings. The spatial modulation of average refractive index in the plane of the liquid crystal cell with the hexagonal structure of bubbles allows us to produce diffraction patterns with hexagonal arrangement of the diffraction maxima. The spacing of the diffraction grating and the periodicity of diffraction pattern can be controlled by using cholesterics of different pitch and by confining them into cells of different thickness. The grating can be switched between the “on”-state (diffraction pattern) and “off”-state (no diffraction) using pulses of AC voltage. Finally, we outline other potential applications of the director structures in the cholesterics, among which are the 1D, 2D, and 3D photonic crystals, diffraction gratings, and switchable color filters. [1]. I.I. Smalyukh, S.V. Shiyanovskii, and O.D. Lavrentovich, Chem. Phys. Lett., 336, 88 (2001). [2]. I.I. Smalyukh and O.D. Lavrentovich, Phys. Rev. E, 66, 051703 (2002). [3]. I.I. Smalyukh and O.D. Lavrentovich, Phys. Rev. Let., 90, 085503 (2003).

For further information, please contact aziz Mahfoud at 229-1390..

Electro-Optics/Physics/ECE Seminar

Friday, April 2, 2004 Science Center Room 119

3:00 P.M

Dr. Ivan Smalyukh

The student members of the Kent State University and the U

niversity of Dayton student chapters.

Electro-wetting for Electro-optics

SPIE Series Lectures

Cincinnati, OH

Physical movement of liquids on hydrophobic dielectrics can be achieved through applicreferred to as electro-wett forms of electro-wetting liquid manipulation are governed by an electrostatically modulated

ches, spatial light modulators, reflective displays, and fluorescent displays.

urther information, please contact aziz Mahfoud at 229-1390..

Science Center Room 119 3:00 P.M

Jason Heikenfeld, Ph.D. Extreme Photonix

ation of electric field, an effect commonly ing. Generally, all

decrease in surface contact angle consistent with an increase in polar liquid wetting (contact area) to a hydrophobic-dielectric. Complementary movement of two immiscible polar and non-polar liquids is also achievable in competitive electro wetting systems.

The now rapidly broadening field of electro-wetting spans multiple applications in electro-optics including variable focus lenses, convex/concave invertible lenses, fiber-optic communications swit

The broad-reaching applicability of electro-wetting in electro-optics stems from the ability to achieverobust and rapid (~ms) changes in physical position, optical surface curvature, or effective refractive index of single or multiple-immiscible liquid systems. Fundamental principles and present status of electro-optic electro-wetting devices developed by Extreme Photonix, and by other groups, will be presented.

For f

Friday, October 8, 2004

Raman Spectroscopy - A Versatile Tool for Characterization of Semiconductor Materials, Devices

and Processes

Martin Herms

Fraunhofer Instit

Raman spectroscopy is ul method for studing properties of compound semiconductor materials, devices and related fabrication processes. After a brief introduction into the general Raman features of GaAs single crystals and

3:00 P.M

SPIE Series Lectures

ute for Nondestructive Testing,Dresden

a usef

the problem of thermal treatment, the possibilities to determine electrical parameters by use of the phonon-plasmon coupling effect with high spatial resolution shall be demonstrated. Emphasis will be placed on the free charge carrier concentration. Special results obtained in GaAsBi layers, as well as studies of the arsenic precipitation in low-temperature grown GaAs by Raman and Small Angle X-ray Scattering, will be presented. Additionally, the talk will give a brief overview of the semiconductor-related activities in the free state of Saxony.

For further information, please contact aziz Mahfoud at 229-1390.

Friday, October 29, 2004 Science Center Room 119

SPIE Annual Meeting

The University of Dayton SPIE student the opportunity of sharing ideas with other student representing 1 th eeting in Denver Colorado last August. Aziz d Yasser abdelaziz represented the University of Dayton in this event. The meeting was full of information

ers

chapt r hade

1 countries at the SPIE 49 Annual M Mahfoud student chapter president an

about student benefits for the student members. The existence of the SPIE Educational Scholarship was a benefit that passed unperceived from us as well as the access to the SPIE Digital Library. The meeting also helps us to brain storm ideas with other membabout possible chapter activities and about programs liket K-12 outreach.

Aziz Mahfoud and Yasser Abdelaziz with the student leaders of the Kent State University and Poland SPIE Student Chapters.

SPIE Student Chapter Underlined in 20th Anniversary University of Dayton Electro-Optics Program

K-12 Outreach Program

have been an objective for the Electro-Optics program of the University of Dayton to romote optics education through organizing experiments and demonstration that

encourage the interest in ense, the University of Dayton SPIE Student Ch rch Laboratory, Sensors Directorate, Air Force Research Laboratory, Materials Directorate, Science

gh

e

Itp

optics in the K-12 environments. In this sapter joint effort wit the Air Force Reseah

Applications International Corporation (SAIC) and the University of Dayton, Electro-Optics Program to bring a series of optics experiments and discussions to junior hischool students. The students were introduced to the concepts of wavelength, frequency, polarization, light source spectrum (LED’s, lasers, incandescent bulbs, etc.), also thstudent had the opportunity to assemble a Keplerian and Galilean Telescopes.

Emily Heckman, Jangpyo Kim and Aziz Mahfoud from University of Dayton, explaining to the students the principles of an optical spectrometer.

Dr. Perry Yaney illustrating a ray optics analysis of a concave lens

Dr. Stanley Rogers from the AFRL-SN, Aziz Mahfoud and Emily Heckman with the last competitors in the knowledge contest.

Visit of Kent State University In order to promote cooperation among chapters, the Student Chapter of University of Dayton visit the Liquid Crystal Institute at Kent State Unviersity. The Liquid Crystal Institute was named in honor of its founder, Dr. Glenn H. Brown, by the Kent State University Board of Trustees in 1986. Kent State University constitutes the center spot for research related with new technologies involving liquid crystal. The members of our chapter had the opportunity to interact with the SPIE students members of Kent State and to understand the hole process of fabrication o liquid crystal.

The students in the cleanroom at Kent State University

Student Annual Meeting

Minutes of the SPIE Student Chapter Meeting

at the University of Dayton (Joint Meeting With OSA and LEOS Student Chapters)

Held on November 4, 2004 in KL341 at 6:15 p.m.

Prepared by Joe Binford, Secretary, on November 5, 2004

1. Attendance

There were a total of twelve people in attendance. Those in attendance included Patrick Berry (Vice President and OSA Student Chapter President), Joe Binford (Secretary), Adam Cooney, Cong Deng, Jang Pyo Kim, Aziz Mahfoud (President), Zasim Mozumder, Georges Nehmetallah, Khan Peksoz, Dave Pikas, Dr. Andrew Sarangan (LEOS Student Chapter Faculty Advisor), and Sree Talluri.

2. Introduction

Aziz Mahfoud gave a brief introduction while those in attendance enjoyed refreshments of pizza and soft drinks. He encouraged members and others to become

to become more involved, listing ideas for educational outreach efforts such as the Wright-STEPP program. He also discussed the possibilities in arranging tours to optics-related companies and bringing speakers to UD to give optics-related talks. Finally, he encouraged students to pursue educational opportunities in writing proposals, applying for scholarship funds, researching information on SPIE’s Optics InfoBase, helping to develop the SPIE Student Chapter website, and generally looking for ways to further enhance one’s professional development in the optics field.

3. Educational Outreach

Aziz Mahfoud dis tics education in the Dayton community entioned the success of the Wright-STEPP pr during the last school year in coo atterson Air Force Base (WPAFB), where students were introduced to the concepts of laser radiation, cs Education Kit receiv and Patrick Berry men or educating

more involved in SPIE Student Chapter activities, including those of the OSA and LEOS Student Chapters. He mentioned that there are many opportunities for students

cussed ways students could encourage op, specifically for K-12 level students. Aziz m

ogram for 10th grade students held peration with the Air Force Research Laboratory (AFRL) at Wright-P

polarization, and spectroscopy. He also talked about the Optied from SPIE for the purpose of educational outreach. Aziztioned the usefulness of videos such as the included IR video f

students prior to demonstrating various optics experiments. Joe Binford mentioned lking with teachers prior to presenting optics demonstrations to students

in their classes. He suggested that this might encourage more teacher involvement

4.

brought up ideas for arranging tours to various optics-related companies in the area. He mentioned our past visit to Kent State University to see the

5.

ziz Mahfoud thanked Jang Pyo Kim for creating the UD SPIE Student Chapter /www.udayton.edu/~spie

the idea of ta

and allow teachers to give our chapter feedback on effective ways to encourage their students to learn more about optical science and technology. Aziz mentioned the need for English speakers in the K-12 educational outreach. Optics Tours/Speakers

Aziz Mahfoud

Liquid Crystal Institute. Ideas for possible tours included Mound Laser in Dayton, Ohio. Dr. Sarangan mentioned the idea of visiting CMC Electronics in Cincinnati, with a possible entertaining trip to Paramount’s Kings Island. Joe Binford mentioned contacting 3M Precision Optics to see if a tour could be arranged. Although it wasn’t brought up, ideas for bringing speakers to UD are also welcomed. The group thought the best time to arrange these optics tours would be on Fridays beginning at 2:00 p.m. or 2:30 p.m. Mention was made to set the tour date on a day after classes are concluded this semester. The UD van could also be used for travel as long as the driver had taken the proper UD driver training.

Other Activities

Awebsite, located at http:/ . He also encouraged other students to get involved in the development of the site. Aziz and Patrick mentioned the desire of many students to obtain access to SPIE’s Optics InfoBase, located at http://www.opticsinfobase.org. They stated that, with a chapter username and password, students will be able to gain access and download the information they need for their optics research. The group also discussed funding issues in the chapter. Aziz and Patrick mentioned the funding opportunities for students from SPIE and LEOS, in addition to those offered through DAGSI. SPIE has an application, available at http://www.spie.org, that allows students to apply for scholarships and travel grants. Funding through SPIE can typically be $3,000 or $4,000 and as high as $10,000. Funding through LEOS may be as high as $5,000. The group agreed that applying for this funding is well worth the effort, especially since the chances are high that the funding will be granted. Dr. Sarangan mentioned that, in regard to travel grants, if SPIE awards one-third of the necessary funding, that the EO department and UD would cover the other two-thirds in most cases. Aziz and Patrick mentioned that the annual funding for the SPIE and OSA student chapters is $500 each. Dr.

arangan mentioned that the annual funding for the LEOS student chapter is about

S$2000.

Conclusion

Aziz Mahfoud encouraged everyone to become more involved in the SPIE/OSA/LEOS student chapters and thanked everyone for coming. He also encouraged everyone to contact him or Patrick

6.

Berry if they had any questions or suggestions. Dr. Sarangan had brought a digital camera and took several pictures of

ance. Hopefully these pictures will be posted on the SPIE student chapter website! Aziz dismissed the meeting at about 7:30 p.m.

the group in attend

University of Dayton SPIE Student Members

Visit to Mound Laser and Photonics Center

Dr. Dosser first brought us to the laser welding area where two of the employees explained the laser welding services provided to their customers. Their primary system consists of a neodymium-doped yttrium aluminum garnet (Nd:YAG) laser with 220 W of optical power at 1064 nm incorporates a 600 µm fused silica step-index optical fiber to deliver the power to thprofile plus one rotation axis ployees explained that this laser system uses re hs to achieve proper weld motive

10. Laser Markin

Next, Dr. Dosser brought our group to see the laser marking/engraving area. Dr. ned the use of the two prim y laser marking systems consisting of 1064 lasers. Both systems incorporate an x-y galvanometer scanning

subassembly with an f-theta field lens to raster the beam over the desired target

Report of the University of Dayton SPIE Student Chapter

Visit to Mound Laser and Photonics Center, Inc. in Miamisburg, Ohio

Held on November 23, 2004 at 12:45 p.m.

7. Attendance

There were a total of nine people in attendance. Those in attendance included Joe Binford (Secretary), Cong Deng, Dr. Joseph Haus (Electro-Optics Program Director), Jang Pyo Kim, Aziz Mahfoud (President), Zasim Mozumder, George Nehmetallah, and Sree Talluri..

8. Introduction

Most of the group met on campus at University of Dayton in KL341 at 12:15 p.m. to travel by van to Mound Laser and Photonics Center, Inc. (MLPC) in Miamisburg, Ohio. Dr. Haus drove the van for our group. Upon our arrival, we met with Dr. Larry Dosser, President and CEO of MLPC, who had agreed to take us on a tour of the facility. Dr. Dosser welcomed us and explained that there are three main services provided by his company: laser welding, laser marking/engraving, and laser micromachining. He encouraged all of us to feel free to look around during the tour and ask any questions that came to mind.

9. Laser Welding

that e target weld area with a "top hat" beam

. The target piece is mounted on a 4-axis assembly (3-D translation ) for accurate positioning of the region to be welded. The em

latively long pulse widts and is commonly requested for components in medical and auto

devices..

g/Engraving

Dosser explainm Nd:YAG

ar

regions of the sample to be marked. Both systems have 4-axis assemblies for mounting parts to be marked. The first system Dr. Dosser showed us produced a beam with about 70-75 W of optical power. The other system produces a power of 90 W. Dr. Dosser mentioned that these systems take off the top layer of material up

a 1 mm depth. Components can be engraved up to a 0.020" depth. Some typical can be marked or engraved with a laser include anodized aluminum,

graphite, and various plastics. The markings that can be made with these systems

11.

yttrium vanadate (Nd:YVO4) laser crystal umped with the fiber-delivered light from a laser diode array. The laser system

of power at 1064 nm, but is frequency-tripled with the crystal to produce the third harmonic at 355 nm. The power at 355 nm is typically 4.5 W with a

by accurately characterizing the system operation. They also discussed e use of a laser sensor for accurately mapping surfaces that were to be machined.

micromachining system is ±0.5 µm with a minimum feature size of 10 µm.

12.

tomaterials that

include logos, 1-D and 2-D barcodes, and alpha-numeric characters.

Laser Micromachining

Finally, Dr. Dosser brought our group to see the laser micromachining area. There, several of the employees explained the processes used in micromachining components for their customers. They explained that the laser micromachining system consists of a neodymium-doped pproduces 18 W

pulse frequency of 20 kHz, operating at just above threshold. At the 355 nm wavelength, the beam can be focused to a 13 micron spot on the component to be micromachined. Again, a 4-axis assembly is used to properly position the sample while a telecentric f-theta lens system following an x-y galvanometer assembly is used to maintain the rastered beam's orthogonality and field flatness to the machining plane. The employees explained that the low pulse energy and high pulse rate were found to perform better for laser micromachining applications. For large components, they explained that stitching algorithms were used to perform micromachining on areas larger than 2" by 2", stating that stitching errors were minimizedthThe resolution for this laser

Conclusion

Overall, our group really enjoyed the tour of MLPC given by Dr. Larry Dosser and thanked him for giving us the opportunity to learn more about his company and the innovative optics work that is being done there. He encouraged us to become more involved in the optics community and to look for opportunities that enhance our professional growth. We took some group photographs and left MLPC at around 2:15 p.m. Most of us stayed to visit the Native American mound for which the site is named. After taking some pictures, we adjourned and returned to the University of Dayton campus at around 3 p.m. More information about MLPC can be found on their website at http://www.mlpc.com on the Internet.

**This article was written by Joe Binford (Secretary) on November 29, 2004

PIE students members with Larry Dossier CEO of Mound Laser and Photonic Center .

Sand Dr. Joseph Haus Electro-Optics Program Director at the company installations

Financial Statement

Inicial Balance 500.00 Date Activity Description Amount 10/8/2004 SPIE sponsored seminar/ Refreshment 32.68 10/29/2004 SPIE sponsored seminar/ Refreshment 41.99 11/04/2004 Student annual Meeting 48.00 Final Balance 377.36