Fast and sensitive nonlinear processes: bistability in CdHgTe

Abstract

We discuss the origin and characteristics of the very large intensity-dependent changes in the refractive index of the semiconductor cadmium mercury telluride at 10.6 m. With continuous wave (c.w.) radiation and sample temperatures of 77 K nonlinear Fabry-Perot effects can be observed at powers as low as 1 mW. The Auger dominated recombination process and the thermal contributions to the refractive index make observations of optical bistability difficult with c.w. radiation. However, the use of a pulsed CO 2 laser and two-photon absorption of the radiation does lead to the observation of bistability at room temperature. We compare these results with the reported work on InSb.