Photorefractive effects in Sn2P2S6
Résumé
Tin hypothiodiphosphate (Sn2P2S6) is a very promising material for photorefractive applications in the red and near-infrared wavelength range. The main advantage of Sn2P2S6 as an infrared-sensitive photorefractive material is its high beam-coupling gain combined with relatively fast response, about two orders of magnitude faster than in the conventionally used photorefractive material BaTiO3 doped with rhodium. Compared to oxide ferroelectrics, which are wide-band-gap dielectrics, Sn2P2S6 crystals are characterized by a narrower band gap (2.3 eV) and a higher photorefractive sensitivity, and are transparent in the range of 530– 8000 nm.