Surface-Emitting Laser Logic

Abstract

Here we describe our efforts to build an ideal optical switch based on the monolithic integration of a heterojunction phototransistor (HPT) with a vertical-cavity surface-emitting laser (VCSEL) diode. To date we have demonstrated high optical gain (> 20 overall, > 200 differential) with the discrete components connected in series. Our devices are ideally suited for parallel optical signal processing which is currently regarded as the most promising research area for achieving significant increases in computational throughput relative to purely electronic based information processing. Parallel optical processing has been severely hampered by the lack of several basic "building block" devices such as optical switching devices that exhibit low-switching energy, high optical gain (fanout capability) and high contrast. Devices should be: easy to fabricate (use of self-aligned VLSI technology), microscopic in size, and readily integrable with other optoelectronic components without being adversely affected by external optical feedback.