Abstract

It has been identified that a fast, low power, dense optical memory system is critical for the development of general purpose optical computing and optoelectronic processing.¹ The present work evaluates the use of the long carrier lifetimes in hetero-doping superlattices in implementing optically addressable optoelectronic memory elements. The device is configured as an asymmetric vertical Fabry-Perot cavity² with about 30% reflectivity from the top AlGaAs-air interface and with AlGaAs/AlAs quarter-wave-stack superlattice mirror at the bottom providing more than 95% reflectivity (Figure 1). A write beam operating in the absorption range for the doping-superlattice creates electron-hole pairs which are promptly separated by the high internal electric field. The spatial separation of the electrons and tire holes causes the ambipolar lifetime to be long, in the range of micro- to tens of milli-seconds, and the device acts as a memory element similar to an electronic DRAM.

© 1993 Optical Society of America