Nonlinear absorption of laser pulses in amorphous and crystalline As2S3 thin films

摘要

Abstract: Results of the experimental investigations of absorption of laser pulses in amorphous (a-) and crystalline (c-) As$-2$/S$-3$/ films are presented. The optical transmission hysteresis and reversible film photodarkening at interband excitation of a-As$-2$/S$-3$/ films in a blue-green spectral region are reported. It was suggested that the nonlinear light absorption could be explained by taking into account the light interaction with nonequilibrium localized lattice vibrations anharmonically coupled with the extended phonons. The measurements of peculiarities of the pulse absorption in crystalline As$-2$/S$-3$/ films can confirm the proposed explanation. !7