Exciton-polaritons in nonlinear optical phenomena in semiconductors: An overview of major developments

Abstract

In the past decade, the availability of techniques for generating very intense tunable ultrashort-pulse laser radiation in the picoseconds and femtoseconds range have made it possible to use time-resolved pump probe techniques for studying the dynamics of the nonlinear response of bulk semiconductors and semiconductor quantum well structures to intense EM beams. Moreover, as a result of interest in nonlinear optical phenomena that might be used in optical memory, logic and switching applications, there has been an intensification of research on the effects of intense EM beams on optical properties in the vicinity of the exciton resonances and optical absorption edges of semiconductors. In this article we present an overview of key experimental and theoretical developments that underlie our understanding of the role played by exciton-polaritons in nonlinear optical phenomena in semiconductors and, in particular, the role played by exciton-polaritons in the nonlinear optical effects, including the optical Stark effect, which result from the virtual excitation of excitons, continuum electron-hole pairs and biexcitons by an ultrashort pulse of intense EM radiation at frequencies below the exciton resonance, and which exist only during the time of the pulse.