Abstract

Transmission of intense, nonresonant, optical pulses at 10.6-μm wavelength through bulk HgCdTe at room temperature is investigated experimentally and theoretically. The incident photon energy is slightly less than twice the energy band gap in our sample. Our experimental results indicate that for incident intensities up to 1 MW/cm² no significant optical nonlinearity takes place. However, at ~1 MW/cm² and higher intensities the transmission drops to zero in ~1 ns. We describe this effect in terms of the absorption of the incident light by the electron plasma in the sample, the plasma being created as a result of the two-photon absorption process of the leading edge of the incident pulse. The theory predicts that, at a threshold of 0.9-MW/cm² incident intensity, the plasma density is sufficiently high for the plasma frequency to be at the incident light frequency which is in good agreement with our experimental results.

© 1985 Optical Society of America