Vitreous films in the Ga-Ge-S(Se) system are prepared through pulsed laser deposition and investigated. An analysis of the data of Raman and energy-dispersive X-ray spectroscopy demonstrates that the composition and structure of the films are similar to those of the monolithic glass. Exposure of the films to radiation with an energy higher than the band gap leads to bleaching of sulfur-based films due to the local oxidation of the films as judged from the data of infrared, Raman, and energy-dispersive X-ray spectroscopy. The replacement of sulfur by selenium in the composition of the films results in the opposite effect: irradiation of the films brings about the photoinduced darkening. Examination of the samples with the use of a scanning electron microscope does not reveal a substantial change in the morphology of the films under irradiation. The observed effect is used to write a copy of the diffraction grating with a resolution of 1200 grooves/mm.