Temperature dependence of the two-photon absorption coefficient of $\mathrm{CdS}_x\mathrm{Se}_{1-x}$ crystals near resonance

An investigation was made of the temperature dependence of the two-photon absorption coefficient of mixed $\mathrm{CdS}_x\mathrm{Se}_{1-x}$ single crystals. When the frequency of laser radiation ($\hbar\omega$ = 1.78 eV) approached the frequency of an exciton transition terminating inside an allowed energy band, the temperature dependence of the investigated coefficient was found to be governed by the temperature dependence of the transverse relaxation time of the intermediate exciton state.