Nonlinearities at the Bandgap in InAs

Abstract

InSb has been shown to exhibit bistability and a very large nonlinear index.1 A semiconductor which is similiar, but which has a bandgap at shorter wavelengths is InAs. In this talk we present measurements of saturable absorption in InAs using an HF laser, which matches the bandgap of InAs at temperatures from 5° to 100° K. Using these measurements we have calculated a nonlinear refractive index of n2 = 2x10−5 cm2/W for light near but below the bandgap. These numbers are comparable to those measured in InSb and indicate that InAs may be a good material for bistable devices.