Jiten Sarathy

Tunable photodetectors based on strain compensated GaInAsSb/AlAsSb multiple quantum wells grown by molecular beam epitaxy

GaInAsSb/AlGaAsSb strain compensated multiple quantum well (MQW) p-i-n structures grown by molecular beam epitaxy on GaSb substrates have been successfully fabricated into tunable photodiodes, which showed a large photoresponse peak shift up to 30 meV (80 nm) at 77 K under a reverse bias of 10 V due to quantum confined Stark effect (QCSE). The QCSE persists up to room temperature and the values of the excitonic absorption peak shifts agree well with the calculated results. Based on the observed QCSE, an electrically tunable resonant cavity enhanced photodetector with strain compensated MQW structure is proposed and modeled.

Resonant cavity enhanced heterojunction phototransistors based on GaInAsSb-AlGaAsSb grown by molecular beam epitaxy

Conventional and resonant cavity enhanced heterojunction phototransistors (RCE-HPT) based on GaInAsSb-AlGaAsSb grown by molecular beam epitaxy (MBE) have been successfully fabricated and characterized for the first time to operate at near 2.2-/spl mu/m wavelength range at room temperature (RT). By incorporating a ten-pair lattice matched AlAsSb-GaSb quarter wavelength reflector, a strong cavity enhancement of the photoresponse at the resonant wavelength has been realized. A factor of 3.8 improvement in the absolute responsivity and an optical gain of 2.2 at the resonant wavelength of 2.16 /spl mu/m at RT have been measured from the RCE-HPT.

A Performance Optimization Method for SOA-MZI Devices

We present a novel characterization method for semiconductor optical amplifier Mach-Zehnder interferometer (SOA-MZI) switches which combines a pump-probe measurement with an interferometer bias scan. This enables optimal bias identification and better understanding of switching dynamics.

Efficient performance optimization of SOA-MZI devices

We present a novel characterization method for semiconductor optical amplifier Mach-Zehnder interferometer (SOA-MZI) switches which combines a pump-probe measurement with an interferometer bias scan. In addition to a wealth of information on the switching dynamics for all operating points of the switch, we can create an extinction map to pinpoint regions of highest extinction for optimizing all-optical ultrafast switching. We experimentally verify the accuracy of this characterization method by performing a wavelength characterization at the optimal bias point and a nearby, non-optimal point. A 1-dB penalty was observed.

Design and applications of all-optical regenerators

The applications and design considerations that drive the development of InP-based all-optical regenerators are summarized. The applications of the 2R regenerator are enumerated along with the design considerations for the fabrication of these devices.

Efficient Performance Optimization for Ultrafast All-Optical Switching in SOA-MZI Devices

We present a simple method for optimization of ultrafast switching performance in semiconductor optical amplifier Mach-Zehnder interferometer (SOA-MZI) devices. By simultaneously measuring switching dynamics over all possible interferometer bias points, we acquire an extinction map which accurately identifies operating conditions for high extinction and optimal switching.

A new architecture for counterpropagation-based photonic regeneration and reshaping

This paper presents the honeycomb architecture for performing photonic regeneration and re-shaping in the counter-propagation. We demonstrate the suppression of undesired gain compression and cross-gain modulation effects along with significant improvement of input power sensitivity.