1. Support: NSF-STC CMDITR
Hybrid Organic-Inorganic for Integrated Optics: Electro-Optic Filters and Modulators
Mahmoud Fallahi
College of Optical Sciences, University of Arizona
Support: NSF-STC CMDITR

2. Group Research Activities
Semiconductor Lasers and
Integrated Photonics
Integrated Optics
and WDM
High Power Semiconductor
Lasers
Sol-gel
Integrated Optics
EO sol-gel/polymer
SLM
High Power Optically
Pumped VECSEL nm
InGaAsP/InP

3. High Power Tunable VECSEL and SHG
Fundamental~976nm
SHG~488 nm (1.3 W)

4. EO Hybrids and Applications
Objective: Development of High-Speed, Low-Voltage, low-Cost Special Light Modulators, Tunable Filters and Switches arrays.
Applications:
Optical Communications and Network security
Optical Correlators and recognition system
Optical Cross-Bar Switching
Real-time beam steering
Holographic Data Storage
3-D Imaging

5. Competing Technologies and our approach
Liquid Crystal: Issues: Slow, retain image, variable contrast and sensitivity across device
Semiconductor EA in MQW Stark effect: Fast, Issues: difficult to make in large array, poor contrast and high voltage, high loss
Magneto-optic of Aluminum Garnet: Low efficiency, High powered drive current
Deformable mirrors (MEMS): Expensive, non-flat, slow (ms)
EO Polymers/Hybrids-based strtucture: Our approach
Combine high bm chromophores with Improved hybrid poling method
Polymers or hybrid organic-inorganic sol-gel as the host
Fabry-Perot Etalon with high finesse and sensitivity
Transparent electrodes inside the cavity for low voltage
2-D Pixelation of SLM

6. Hybrid Organically-Modified Sol-Gel
Sol-gel: Chemical route for production of glass material
from Metallorganic precursor.
Advantages:
Low Temperature Processing (<250 C)
Crack Free Thick Film Deposition
Refractive Index Tuning
Low Loss Waveguides
Photo-Patternable
High Tg and High Stability
Low Cost
Electro-Optic Components by Chromophore Doping

7. Sol-gel Synthesis of organoaluminosilicate2 C=
C(CH 3
)CO
(CH )
Si(OCH +
0.01M HCl (R=1)
Stir 30 min
organically modified
silicon-alkoxide
(MAPTMS)
Stir 30 min
Al(C H O) 4 9 3
metal-alkoxides
Hydrolysis &
Cross-linking H
O (R=2) 2
Stir 30 min
Stir C 10 H 12 O 2
Age 24 hrs
photoinitiator
Spin coat o
Bake at 100 C
Hard Bake
UV/Develop

8. Nonlinear Chromophores
TCBD
36 pm/V in sol-gel
DR1
DR13
DR19
AJL8
33 pm/V in APC
AJLs102
78 pm/V in APC

9. Fabry-Pérot Étalon: Design
Structure 1 V
Glass
DBR
Structure 2
Epoxy V
EO Polymer
ITO
In2O3
Structure 3
Better TCO V
Fabry-Perot (FP) etalons can be designed and fabricated adopting 3 different structures. The Structure 1 has been previously applied using indium tin oxide (ITO) electrodes outside FP etalon cavity for reduced optical loss. The homemade ITO electrodes have very good conductivity however fairly large absorption at ~1550 nm. With new indium oxide (In2O3) oxides, we are able to increase the effect voltage ratio and achieve a higher operation speed using Structure 2. We are looking forward to finding even better transparent conducting oxide with good optical transparency, conductivity and thermal stability so that we can further improve the FP etalon performance.
The R of ITO in Structure 1 is small but RC constant is still large due to the large resistance loaded by DBR.
Light Path

10. Review: EO Sol-gel Tunable Filter
EO polymer: TCBD coupled hybrid sol-gel
Étalon structure 1 with ITO electrodes
Large tunability (0.75 nm/V), high finesse (~235), wide tunable range (>50 nm)
35 dB isolation ratio with10 V
Appl. Phys. Lett. 89 (2006),

11. Review: Hybrid Fabry-Pérot Étalon
EO polymer: AJL8/APC
Étalon structure 2 with ITO & In2O3
Large tunability (0.4 nm/V), high finesse (~234), low insertion loss (~4 dB)
10 dB isolation ratio with 5 V
10 % modulation with 5 V at 200 kHz
Modulation depth = 10%
Drive voltage Vp=5V
Appl. Phys. Lett. 89 (2006),

12. SLM - Photomask Design
* Applicable pattern ranges from 4×4 to 16×16 each 1cm × 1cm.

13. SLM - Substrate Fabrication
Patterned 8×8 ITO substrate
Patterned 16×16 ITO substrate
Patterned 4×4 ITO substrate w/
DBR coated & wires attached
Patterned 8×8 ITO substrate w/
EO polymer AJL8/APC spin-coated

14. SLM - Integration & Testing
Patterned 8×8 ITO/DBR Substrate
Electrically poled
In-house fabricated 8×4 SLM
Optical testing set-up

15. 4x8 SLM - Testing Results 4 x 8 SLM with ITO outside electrodes
Transmission through part of SLM (part of 4 pixels) with a broadband source (~1550 nm ± 25 nm)
4 x 8 SLM with ITO outside electrodes
Resonance transmission through 4 pixels with a 1558 nm laser with no applied voltage.
Modulated image under biased voltage
Field applied to all pixels