  We calculate the dispersion of the plasmon-LO modes taking into account the
spatial dispersion of the electronic polarizability. It is shown that
stimulated emission of the plasmon-LO mode is possible in the frequency range
corresponding to the Reststrahlen band of GaAs both in a 6 nm wide HgTe/CdTe QW
and in a 5 nm wide HgTe/Cd0.7Hg0.3Te QW grown on the (013) plane. Due to the
anisotropy of the dispersion law for the plasmon-LO mode, the [03-1] direction
appears to be optimal for generation.

Mesoscale and Nanoscale Physics