The focus of this research is on the investigation of structural changes in the As2S3-Se multilayer nanostructure and on the examination of a relative contribution of As2S3 and Se layers to nanostructuring by measuring the Raman spectra. The formation of the As2S3-Se nanostructure by an alternate As2S3 and Se layers deposition was applied. The diffraction efficiency dependence on the exposure of a CW DPSS laser were monitored in a transmission mode of the1st order diffracted beam intensity and measured in real-time at the normal incidence of the laser diode beam (λ = 650 nm). From the comparison of these dependences for a set of samples we have chosen the multilayer nanostructure As2S3-Se with optimal recording properties meaning maximum both the value and the rate of diffraction efficiency. Our results are found to be of practical interest as they allow a significant improvement of the diffraction efficiency of the directly recorded relief gratings.