Band structure effects determining the frequency dependence of the third-order susceptibility in semiconductor superlattices

Abstract

It has been shown that semiconductor superlattices can be engineered to achieve a significant enhancement of the higher order virtual susceptibilities. These studies also reveal that the strength of the optical transitions between minibands originating from different regions of the wave vector space reflect the microscopic character of the superlattice wave function. However, this relationship has not been systematically studied and neither its precise origin nor its impact upon the spectral shapes can be understood in terms of the standard language of band theory. Accordingly, in the present study, we show that the spectral shape of the frequency-dependent third order susceptibility of such a system (e.g. AlSb-InGaSbAs) in a sensitive function of novel cancellation processes that reflect not only the position in energy but also the widths and the shape throughout the momentum space of the superlattice minibands spanning the energy range of the order of the fundamental gap away from the band edges.© (1992) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.