Dynamic interferometer on the base of Sn2P2S6 photorefractive crystal modified by indiffusion of Cu

Abstract

Introduction: The photorefractive parameters of the Sn 2 P 2 S 6 single crystals modified by different ways (doping, post-growth treatment) permit to realize the dynamic interferometers. A specific interest represent the samples with strong compensation process. Purpose: This article is devoted to consideration of usage of the Sn 2 P 2 S 6 crystal modi­fied by an indiffusion of the Cu atoms as an active element of the dynamic interfe­rometer, and analyzing of its frequency parameters. Results: The diffusion-modified Sn 2 P 2 S 6 sample demonstrates an increased com­pen­sation of the photorefractive gratings that manifests itself in the complex dyna­mics of the stationary energy transfer. This peculiarity is also observed in the frequency spectra mea­sured at the phase modulation of the interacting beams. These frequency spectra of the first and second harmonics, as well as the corresponding stationary component, are obtained and analysed. Conclusion: The dynamic interferometer on the basis of the Cu-doped Sn 2 P 2 S 6 with strong gain compensation allows to construct the band-pass frequency filters, and also to study the two-wave mixing gain spectrum using frequency-modulation technique.