Changes in the transmission, absorption edge and refractive coefficient in the UV-VIS and the transmission in the IR spectrum of thin As-Ge-S films after irradiation with an argon laser with lambda=488 nm were studied. X-ray microanalysis showed that the composition of the films (with small variations) corresponded to that of the initial substances. Films with a defined concentration of the elements could also be deposited by evaporation of As2S3 and GeS2 from two sources. The optical properties of thin firms prepared by thermal evaporation, flash evaporation and coevaporation from two crucibles have been compared. It was found that depending on the component content, both photodarkening and photobleaching coatings in a wide region of lambda can be obtained in thin As-Ge-S films, The results have been explained from the viewpoint of the photostructural changes in chalcogenide layers.