Experimental investigation of the infrared absorption saturation in p-type germanium and silicon

Abstract

We investigate the room‐temperature absorption saturation of p‐Ge and p‐Si for several samples over a range of doping densities for light having wavelengths of 10.6 and 9.6 μm. The transmission data can be fairly well described using an intensity dependent absorption coefficient characteristic of an inhomogeneously broadened two‐level system. Measurements of the saturation intensity of p‐Ge show that I_s increases monotonically with increasing hole concentration, and that the resonant transition is significantly easier to saturate in p‐Ge than in p‐Si for the samples we examined.