Acoustoelectric domain induced transparency in tellurium at 11 microm.

A drastic increase of transmission was observed in tellurium at wavelengths near 11 microm for a polarization E ||C, if an acoustoelectric domain is present. This behavior is opposite to the observations made with other semiconductors. It is assumed that the absorption, which is caused by an intervalence band transition, decreases due to carrier heating and increased damping in the field of the acoustoelectric domains. Other effects, such as the Franz-Keldysh-type optical transitions, seem to be of much less importance. From comparison of the experimental results with numerical data of the p-band absorption a carrier temperature of 2000 K and damping of 81 meV are estimated.