Photoconductive Mixing in CdSe Single Crystals

Abstract

The mixing of the first four axial-mode frequencies of a ruby laser in a bulk, room temperature, CdSe crystal to obtain microwave beat frequencies in the 1–5 Gc/sec range is described. A photoconductive mixing analysis based on a monomolecular recombination process is found to give excellent agreement with the experimental data. The beat frequency power was found to vary as the square of the dc bias voltage applied across the crystal, the square of the incident light power, and inversely as the square of the beat frequency. A minimum lifetime of 10−9 sec, a cross section of 1.3×10−16 cm2, a modulation index of 0.2, and a maximum beat frequency power of 0.2 mW were obtained in the experiments.