Double Phase Conjugate Mirror with Sb-Doped Sn_2P_2S_6 Crystal for Different Incident Angles, Crystal Thickness, Total Incident Intensity and Polarization

摘要

We developed photorefractive Sb-doped Sn_2P_2S_6 samples of different crystal thickness to investigate the properties of the media for double phase conjugation. The Sn_2P_2S_6 :Sb crystals have high coupling coefficient of 20 cm~(-1), and show fast response time of 1.3 ms at total incident intensity of 0.3 W/cm~2. The maximum phase conjugate reflectivity of 32% was observed with a 4 mm thickness sample. To investigate the characteristics of Sn_2P_2S_6 :Sb for double phase conjugation, on the basis of the coupled wave equations, we showed the dependence of phase conjugate reflectivity on incident angle, crystal thickness, total incident intensity and polarization. From these results, the optimum incident condition was clarified for obtaining the highest phase conjugate reflectivity.