STUDY OF OPTICAL DIFFERENCE MIXING IN Ge AND Si USING A CO2 GAS LASER

Abstract

Measurements are made of the nonlinear optical effect third order in electric field strength in Ge and Si using a CO₂ laser operating at 10.6 μ and 9.2 μ. The effect is due to bound electrons and is described by a fourth‐rank electric susceptibility tensor. The crystals show anisotropy in the nonlinear coefficients whose absolute values are consistent with Miller's phenomenological theory. Comparison is made with the measured values of calcite.