1. TASK 2 InP Traveling Wave Microresonator Filters
Cem Ozturk and Nadir Dagli
University of California
Santa Barbara, CA
Tel: (805) ;

2. Objective Implementation of compact, tunable band-stop and band-pass filters integrated on the common platform for the SG-DBR and wavelength converter. Approach To employ traveling wave micro-resonator devices with adjustable gain. Accomplishments Various micro-resonator device structures are studied and designed. Process development for fabrication is completed. Fabrication of a full chip is underway.

3. General Resonator Overview
Cavity
DFR= b(l) LCavity
Input
Output
Resonance : DFR = 2mp

4. Resonator Transfer Functionk2
The amount of power coupled in per pass aR
The round-trip loss inside the resonator

5. Integration to the common platform allows lateral coupling only.
Challenge 1
Integration to the common platform allows lateral coupling only.
Active WG Structure
1.9 mm
Passive WG Structure
1.9 mm
2265 A
Common WG Core

6. Challenge 2 WG Resonator
Compact design requires highly confined deeply etched waveguiding for the resonator cavity, making lateral coupling very challanging.
Resonator WG
WG Core

7. Challenge 3
Resonator and the communication channel can overlap to increase coupling, but this creates undesirable reflections to the laser.

8. Challenge 4
For Microdisc-Microring Resonators gain can be limited due to non radiative defects that may be created by deep etching.

9. Microresonator Cavity with TIR Mirrors
Active material
Input
Output L

10. Employing S-Bend Couplers is not practical
S-Bend Simulations
Employing S-Bend Couplers is not practical
L = 200 mm, Dx = 5 mm
W = 3 mm, T = 2.0 mm
Lstraight = 5 mm
L = 40 mm, Dx = 1 mm
W = 3 mm, T = 2.0 mm
Lstraight = 5 mm, g = 4.5 mm
Too Long
No Appreciable Coupling

11. Designed Travelling Wave TIR Mirror Resonator Band-stop Filters

12. TIR Mirror Design
SiN Mask
SiO2 Mask

13. FDTD SIMULATIONS
R = 90%

14. PROCESS DEVELOPMENT

15. Compatible Fabrication Process

16. Chip Layout

17. Devices Under Fabrication
Microdiscs
WGs
Mirrors
Active Region After Regrowth

18. Summary
Novel traveling wave resonator filters utilizing the existing material platform were developed, designed and simulated.
We also designed and developed a fabrication process compatible with the fabrication of SG-DBR and wavelength converters.
These filters can readily be integrated with other devices on the same platform.
Fabrication of these filters are underway.

19. Future Work
Improvement of the free spectral range by making the coupling of power into the resonator wavelength selective.
Integrate filters with wavelength converters.
Demonstrate electronic tuning.
Demonstrate multi wavelength operation.