Two-photon absorption in InSb and Hg1-xCdxTe

Abstract

Two-photon absorption measurements on InSb, obtained with a single mode hybrid CO₂ laser, have been analysed, taking into account the fact that the laser is Gaussian in space and the effect of free-hole absorption on the temporal profile. The dependence on wavelength of the two-photon coefficient at room temperature (K₂=8 cm(MW)^-1 for 10.6 mu m and K₂=14 cm(MW)^-1 for 9.6 mu m pumping) agrees well with a new calculation including the effect of non-parabolic bands. A similar measurement on Hg_0.78Cd_0.22Te (K₂=14.0 cm(MW)^-1 for 10.6 mu m pumping) is consistent with this.