Abstract

1. Introduction Recently, it was demonstrated that GaAs/AIAs superlattices could be changed from an indirect material to a direct one by applying an electric field.¹ In InAlAs/AlAsSb multiple quantum wells² radiative lifetime was varied from 220 ns to 5 μs. Stimulated emission in indirect gap GaAlAs was also observed.³ Recently, it was demonstrated that GaAs/AIAs superlattices could be changed from an indirect material to a direct one by applying an electric field.¹ In InAlAs/AlAsSb multiple quantum wells² radiative lifetime was varied from 220 ns to 5 μs. Stimulated emission in indirect gap GaAlAs was also observed.³ The existence of an indirect energy gap in superlattices can be used to implement optica! amplifiers with low cross-talk by sacrificing gains. Furthermore, Q-switched lasers may be possible by using the quasi-indirect transition, similar to the 1.064-pm transition in a Nd: YAG laser. During this presentation we report our growth and characterization of GaAs/AIAs superlattices as the first attempt for eventually using these structures for applications in amplifiers and lasers.

© 2002 Optical Society of America