基于KNSBN∶Cu晶体的光折变联合变换相关器

PHOTOREFRACTIVE TWO-BEAM COUPLING JOINT TRANSFORM CORRELATOR WITH KNSBN∶Cu CRYSTAL

给出基于 KNSBN∶ Cu晶体的光折变二波耦合联合变换相关器 ( TBJTC) .以KNSBN∶ Cu晶体作为平方律转换器 ,将强度较大且携带参考图象和待识别图象联合频谱的信号光波与一强度较弱的相干平面参考光波同时输入于 KNSBN∶ Cu晶体 ,通过光折变二波耦合过程的非线性能量转移 ,实现功率谱转换 ,进而实现相关识别 .理论分析和实验结果表明 ,除输入输出外 ,该光学相关器无需 CCD、L CLV等器件和相应的数字处理 ,是一个全光光学相关器 .

It presents a photorefractive two beam coupling joint transform correlator(TBJTC) with KNSBN∶Cu crystal.As a square law detector,a KNSBN∶Cu crystal sample is placed on the spectral plane to record the joint transform spectra of the target image and reference image.And at the same time,a coherent collimated beam(as reference) is input in the crystal to take two beam coupling with the joint transform spectra (as signal).In certain geometry,the coupling will induce such a result,that the energy of the signal beam will be nonlinearly transferred to the reference beam,and the magnified reference beam will include the information of the joint power spectra,so that the correlation recognition is achieved.It is shown that this correlator is an all optical correlator,which need not CCD,LCLV and special digital processing.