This paper discusses the structural changes induced by laser radiation with wavelength λ = 800 nm, pulse width = 100 fs, and repetition rate f=80 MHz in bulk samples of glassy semiconductors. As a result of this work, waveguide structures were created in As₂S₃ and 0.15(Ga₂S₃)-0.85(GeS₂):Er ³⁺[C(Er³⁺)= 1.2 at%] glasses under various conditions of laser action (the recording method, the speed and number of scans). The structural changes induced by fem- tosecond laser radiation in a sample of As₂S₃ glass were investigated by Raman scattering.