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US Army RDECOM/AMRDECUS Army RDECOM/AMRDEC depts. Ashley MORPH 2008 March Ver_7.pdf 2 50 84.0 78.9 82.1 N/A 81.7 60 0 70.0 80.0 90.0 20.0 30.0 40.0 50.0 60.0 r33 (pm/V) 0.0 10.0 NB1

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Text of US Army RDECOM/AMRDECUS Army RDECOM/AMRDEC depts. Ashley MORPH 2008 March Ver_7.pdf 2 50 84.0 78.9...

  • UNCLASSIFIEDUNCLASSIFIED

    Modulator Evaluation and DemonstrationModulator Evaluation and Demonstration

    Paul Ashley

    US Army RDECOM/AMRDECUS Army RDECOM/AMRDEC Redstone Arsenal, AL 35898

    March 19, 2008March 19, 2008

  • UNCLASSIFIEDUNCLASSIFIED

    Outline

    Current status of the evaluation of packaged modulators from Lumera Corporation.

    Current status of the investigation of the effect of thin buffer layers on poling.

    Plans for transition opportunity modulator demo for military/space applications.

  • UNCLASSIFIEDUNCLASSIFIED

    Thermal Stability of LPD80

    Thermal stability of the modulators were evaluated by monitoring the Vπ at the storage temperature of 800C. (Data provided by Lumera Corpration)

    Two-parameter KWW model and Jonscher model were used in predicting the usable lifetime of the devices over 5 10 year periodusable lifetime of the devices over 5-10 year period.

    The distribution width of relaxation times (0 < β < 1)

    Jonscher Model

    relaxation times (0 < β < 1)

    KWW Model

    The average relaxation time constant

    • R. Kohlrausch, Ann. Phys. (Leipzig) 12, 393 (1847) • G. Williams and D. C. Watts, Trans. Faraday Soc. 66, 80 (1970)

    Jonscher model was preferred because of the its consistency with causality

  • UNCLASSIFIEDUNCLASSIFIED

    Thermal Stability of LPD80

    Ignored Average of 5 data sets Normalized (Vπ = 1.0 V at t=0)

    1.5

    Jonscher Model

    Error bars represent the standard deviation Coefficient of determination (r2 = 0.96)

    1.1

    1.3

    V_ pi

    V π (V

    )

    τ = 606168 hrs β = 0.22

    ( )

    0 500 1000 1500 2000 2500 Ti (H )

    0.9

    1.4

    1.6

    _p i(V )Predictions were made up to

    10 b t l ti th

    Time (Hrs)

    1.2

    V_V π10 years by extrapolating the fitted curve. In 5 yrs, Vπ = 1.56 ± 0.01 V

    In 10 yrs, Vπ = 1.65 ± 0.02 V With KWW model, 5 & 10 year predictions were 1 60 V d 1 70 V ti l

    0 2 4 6 8 10 Time (Years)

    1.01.60 V and 1.70 V respectively.

    The differences in the predicted values of the models become significant at t >> τ (~ 70 yrs).

  • UNCLASSIFIEDUNCLASSIFIED

    Thermal Cycling

    Linear ramp : 300C 800C 300C Ramp rate : ~ 0 6 0C/minRamp rate : 0.6 C/min Vπ, Modulation Depth, and Total Insertion Loss were monitored in real time.

  • UNCLASSIFIEDUNCLASSIFIED

    Thermal Cycling : Summary

    Vπ(V) 3.2 Vπ(V) 3.3 Vπ(V) 3.2

    300C 300C

    850C

    300C 300C

    850C 3.2

    TIL (dB)

    9.9

    Mod Depth 11 6

    3 3

    TIL (dB)

    9.3

    Mod Depth 11 2

    3.2 TIL (dB)

    9.5

    Mod Depth 11 630 C 30 C

    2 hrs 30 C 30 C

    3 hrs Depth (dB)

    11.6 Depth (dB)

    11.2 Depth (dB)

    11.6

  • UNCLASSIFIEDUNCLASSIFIED

    Thermal Cycling : Vπ

    755

    60

    75

    )

    4

    5

    ) )

    45

    Te m

    p( C

    )

    3

    V_ pi

    (V )

    pe ra

    tu re

    (0 C

    )

    V π (V

    ol ts

    )

    30

    T

    2

    V

    Te m

    p

    Initial modulation depth ~ 11.2 dB

    Final modulation depth ~ 11.5 dB

    0

    15

    0

    1 Modulation depth varied during the thermal cycle. Mechanical instability in the input fiber connector is suspected.

    0 0 50 100 150 200

    Time (min)

    0

  • UNCLASSIFIEDUNCLASSIFIED

    Thermal Cycling : TIL (2nd cycle)

    7510 5

    11.0

    60

    75

    10.0

    10.5

    (d B

    )

    45

    Te m

    p( C

    )

    9.5

    TI L

    (d B

    )

    er at

    ur e

    (0 C

    )

    er tio

    n Lo

    ss (

    30

    T

    9.0

    T

    Te m

    pe

    To ta

    l I ns

    e

    0

    15

    8 0

    8.5

    0 0 50 100 150 200

    Time (min)

    8.0

  • UNCLASSIFIEDUNCLASSIFIED

    Thermal Cycling : TIL (1st cycle)

    10

    11.0

    60

    75

    10.0

    10.5

    C )

    45

    em p(

    C )

    9.5

    TI L

    (d B

    )

    pe ra

    tu re

    (0 C

    n Lo

    ss (d

    B )

    30

    T

    9.0

    T

    Te m

    ta l I

    ns er

    tio n

    0

    15

    8 0

    8.5T ot

    0 5 30 55 80 105 130 155

    Time (min)

    8.0

  • UNCLASSIFIEDUNCLASSIFIED

    Photobleaching

    0 035

    0.040 AJ 416

    n 0 025 0.030

    0.035 AJ 416 AJ 309 AJ 404 LPD 80 AJ-CKL1

    Photobleached time : 8 – 16 hrs

    Δ

    0.015

    0.020

    0.025

    UV intensity : 7.9 mW cm-2 (@ 365 nm)

    0.005

    0.010

    0.015

    Time (hrs) 0 4 8 12 16

    0.000

    0.005

    Time (hrs)

  • UNCLASSIFIEDUNCLASSIFIED

    Preparation of Test Samples for the Measurement of E-O Coefficients

    Fabrication of buffer layers on ITO coated glass substrates : Northwestern Univ. Core (AJ-CKL1 in APC) provided by Univ. of Washington Fabrication of polymer layer and gold electrodes :Fabrication of polymer layer and gold electrodes : AMRDEC, Redstone Arsenal

    Poling and removal of gold : by AMRDEC, Redstone Arsenal E-O measurements : Laboratory for Physical ScienceE O measurements : Laboratory for Physical Science

    Sample Buffer

    Thickness Sample (nm)

    ITO/Polymer 0

    ITO/SiO2/Polymer 50

    6 mm diameter

    ITO/SiO2/Polymer 280

    ITO/TiO2/Polymer 50

    ITO/TiO2/Polymer 250

    ITO/In2O3/Polymer 50

    ITO/In2O3/Polymer 250

  • UNCLASSIFIEDUNCLASSIFIED

    Poling Parameters using AJ-CKL1 E-O Polymer

    Polarity: negative on top electrode Voltage: 70V/μm (based on thickness of core material only) Voltage is turned on at the temperature of 25ºCVoltage is turned on at the temperature of 25 C Temperature: ramp at 10ºC/min from 25ºC to 135ºC Dwell time at 135ºC: 30 sec Cool down from 135ºC to 25ºC within about 5-6 min. Voltage is turned off at the temperature of 25ºC

  • UNCLASSIFIEDUNCLASSIFIED

    Poling Process for AJ-CKL1/APC without buffer layer

    Polymer thickness = 2.3 μm

  • UNCLASSIFIEDUNCLASSIFIED

    AJ-CKL1 Low Temperature Current Peak

    α γ

    Double Current Peak in single layer poling Typically indicates a low temperature dipole alignment peak (α) followed yp y p p g p ( ) by a higher temperature conduction peak (γ) These peaks are generally coincident in materials previously evaluated

    α

    γ

    Double Current Peak in buffer layer poling Plot shows a much smaller peak for the 50 nm TiO2 buffer layerp 2 y No discernable peaks in thicker TiO2 or either of the SiO2 samples Indicates boundary charge layer is damping the signal

    • Need to investigate boundary charge effect on dipole relaxation

  • UNCLASSIFIEDUNCLASSIFIED

    Poling Process for AJ-CKL1/APC With SiO2 Buffer Layer

    Buffer : 50 nm SiO2 Polymer : AJ-CKL1 in APC

    Buffer : 280 nm SiO2 Polymer : AJ-CKL1 in APC Polymer : AJ CKL1 in APC

    Polymer thicknes = 2.4 μm Poling Voltage = 167V

    y Polymer thicknes = 2.4 μm Poling Voltage = 167V

  • UNCLASSIFIEDUNCLASSIFIED

    Poling Process for AJ-CKL1/APC With TiO2 Buffer Layer

    Buffer : 50 nm TiO2 Polymer : AJ-CKL1 in APC

    Buffer : 250 nm TiO2 Polymer : AJ-CKL1 in APC Polymer : AJ CKL1 in APC

    Polymer thicknes = 2.4 μm Poling voltage = 167V

    y Polymer thicknes = 2.4 μm Poling voltage = 167V

  • UNCLASSIFIEDUNCLASSIFIED

    Experimental Results

    r33 (pm/V) at 1310nm

    S l Thi k ( ) #1 #2 #3 #4 AVGSample Thickness (nm) #1 #2 #3 #4 AVG

    NB1 No Buffer-1 0 N/A 74.0 N/A 67.0 70.5

    NB2 No Buffer-1 0 55.0 55.0 55.0 N/A 55.0

    SI280H SiO2 280 40 0 42 2 46 6 40 0 42.2SI280H SiO2 280 40.0 42.2 46.6 40.0 42.2

    SI50H SiO2 50 39.3 44.0 34.6 38.1 39.0

    TI250H TiO2 250 N/A 85.0 N/A 82.0 83.5

    TI50H TiO2 50 84.0 78.9 82.1 N/A 81.7

    60 0

    70.0

    80.0

    90.0

    20.0

    30.0

    40.0

    50.0

    60.0

    r3 3

    (p m

    /V )

    0.0

    10.0

    20.0

    NB1 NB2 SI280H SI50H TI250H TI50H Measured by Laboratory for Physical Science

  • UNCLASSIFIEDUNCLASSIFIED

    Preparation of Test Samples for Conductivity Measurements

    Sample Buffer

    Thickness (nm)

    Fabrication of buffer layers on ITO/Au coated glass substrates : by Northwestern Univ. Core (AJ-CKL1 in APC) provided by Univ. of Washington

    ITO/Polymer 0

    Au/Polymer 0

    ITO/SiO2 50

    Fabrication of polymer layer and gold electrodes : by AMRDEC, Redstone Arsenal Conductivity measurements : by NAVAIR, China Lake

    ITO/SiO2 280

    ITO/TiO2 50

    ITO/TiO2 250

    ITO/In2O3 50

    ITO/In2O3 250

    Au/SiO2 50

    Au/SiO2 280

    Au/TiO2 50

    Au/TiO2 250

    3- 4 mm diameter

    Au/In2O3 50

    Au/In2O3 250