Experimental Study Of Photorefractive Adaptive Optical Heterodyne Detection System

The key technology of photorefractive adaptive optical heterodyne is studied in this paper. The phase conjugation properties of self-pumped phase conjugation(SPPC), mutually pumped phase conjugation(MPPC), self-pumped phase conjugation and mutually pumped phase conjugation coexisting(SPPC-MPPC coexisting) are studied with photorefractive crystal, and the dependences relationship between their output properties and pump parameters are obtained experimentally. The influence on SPPC reflectivity is researched experimentally and theoretically, when the polarization state of pump laser is changed by passing through optical system. Two equations are theoretically studied. One is a polarization equation that describes the polarization state change of the reflected light by a beam splitter. The other one is a polarization state response equation of the coupling coefficient in the photorefractive crystal Cu:KNSBN. The relationship between light coupling coefficient and incidence angle of laser is achieved and obtained mathematic simulation results. The theoretical results are consistent with that of experiment. Based on the effect of SPPC-MPPC coexisting in the photorefractive crystal, using the new photorefractive adaptive optical heterodyne detection system, the effect of the local optical intensity on the output signal in heterodyne detection system is done experimentally. The response time of the new photorefractive adaptive optical heterodyne detection system is also indicated.The study of photorefractive adaptive optical heterodyne detection system in the paper is useful to the real application of optical heterodyne detection.