MIT Department of Electrical Engineering & Computer Science

Wafer-Fused Optoelectronics for Switching

Ali Shakouri
University of California, Santa Barbara

Tuesday, April 28, 1998
4:00 PM (refreshments 3:45)
Grier Room, Room 34-101B
EECS Special Seminar

Abstract

Optical fibers with their virtually unlimited bandwidth are used for transmission in telecommunication networks. Routing and multiplexing are usually performed electronically. To overcome the problems of electronic packet switching at very high speeds (>40 Gbps), we are investigating a solution based on almost all optical networks. In this talk various design aspects of different components are discussed. In particular, a crossbar switch based on fused vertically-coupled waveguide structures is introduced. Beam propagation analysis shows that very short coupling lengths (40-220 microns) with good extinction ratios (20-32 dB) are achievable. The designs can be further improved to increase these extinction ratios to 35-40 dB using a slight asymmetry in the waveguide structure. The optical loss at the fused interface is characterized at 1.55 microns. The experimental results for an InP/InGaAsP based passive fused vertical coupler and a switch with ultra short coupling length of 62 microns will be presented. This approach can be used to make three-dimensional photonic integrated circuits with multiple levels of photonic interconnects.