Share Email Print

Proceedings Paper

All-optical devices realized by the post-growth processing of multiquantum-well structures
Author(s): Patrick LiKamWa; Ayman M. Kan'an; Mitra Dutta; Jagadeesh Pamulapati
Format Member Price Non-Member Price
PDF $17.00 $21.00

Paper Abstract

An inexpensive and reliable process for the area-selective disordering of MQW structures is reported. The method relies on the diffusion, by rapid thermal annealing, of surface vacancies into the quantum wells thereby intermixing the Ga and Al atoms between the wells and barriers. A silicon oxide cap that is formed by curing a spun-on solution of glass forming compound acts as porous layer that enhances the formation of surface vacancies by allowing out-diffusion of Ga and Al atoms. This technique has been applied to the fabrication of two integrated optical devices. One is the nonlinear zero-gap directional coupler with disordered input and output branching waveguides, and the other is the symmetric nonlinear integrated Mach-Zehnder interferometer with one arm containing a non-intermixed MQW section. In both devices, the mechanism for the switching is the nonlinear refractive index that is caused by photo-generated carriers. Since this mechanism entails absorption of some of the pump beam, it is hence very important that the optical absorption be confined to the active sections only. Selective area disordering is shown to be very effective at defining regions of different bandgap energies. Hence it can be ensured that the energy of the pump laser beam is too low in comparison to the bandgap energy of the passive regions to be absorbed and the free carriers are only created in the non-intermixed active sections. The devices investigated using a pump-probe setup, exhibited strong all-optical switching behavior with a contrast ratio of better than 7:1. The controlled selective area intermixing of MQW structures will potentially play a significant role in the advancement of photonic integrated circuits.

Paper Details

Date Published: 22 January 1997
PDF: 8 pages
Proc. SPIE 3006, Optoelectronic Integrated Circuits, (22 January 1997); doi: 10.1117/12.264227
Show Author Affiliations
Patrick LiKamWa, CREOL/Univ. of Central Florida (United States)
Ayman M. Kan'an, CREOL/Univ. of Central Florida (United States)
Mitra Dutta, Army Research Lab. (United States)
Jagadeesh Pamulapati, Army Research Lab. (United States)

Published in SPIE Proceedings Vol. 3006:
Optoelectronic Integrated Circuits
Yoon-Soo Park; Ramu V. Ramaswamy, Editor(s)

© SPIE. Terms of Use
Back to Top
Sign in to read the full article
Create a free SPIE account to get access to
premium articles and original research
Forgot your username?