Room Temperature Excitonic Nonlinear Absorption in GaAs/AlGaAs Multiple Quantum Well Structures Grown by Metalorganic Chemical Vapor Deposition (MOCVD)

Abstract

Room temperature excitonic nonlinear absorption in multiple quantum wells (MQW) has great potential for making low-power high-speed optical switching devices. The required ultrathin multilayers have been grown by both molecular beam epitaxy (MBE) and metalorganic chemical vapor deposition (MOCVD). Efficient, narrow-linewidth luminescence and low-threshold laser operation have been achieved in MQW’s with both techniques. However, virtually all of the reported work to date dealing with nonlinear optical properties has employed MBE-grown materials CHEMLA /1/, CHEMLA /2/, MILLER /3/. The implementation of arrays of photonic switches in optical computing and processing systems will require large area devices with uniformity that exceeds the capability of current technology. The potential advantages of MOCVD for large area, multiple wafer growth of these complex structures provides motivation to explore this technique for their fabrication. In this paper, the growth by MOCVD of GaAs/AlGaAs MQW structures that exhibit narrow-line, room temperature excitonic absorption are reported. We further describe the linear and nonlinear optical properties of these structures and discuss the implications of this work for the construction of large area arrays of switches.