基于相位共轭的动态体全息衍射特性的实时非破坏性测量

基于相位共轭技术,提出了一种动态体全息衍射特性的实时测量方法.在光学系统设计中,通过调整使得物光和参考光较强,而与参考光共轭的再现光非常弱（约为参考光的1/1 000）,借助非常微弱的共轭再现光实现了动态体全息的非破坏性实时测量.三束光的强度和偏振态可通过1/4波片、偏振片和衰减片进行调节和组合,可记录光强调制型或偏振态调制型体全息.本方法适合于光致折射率变化和光致变色材料体全息的测量.

Real-time Non-destructive Measurement of Diffraction Characteristic of Dynamic Volume Holograms Based on Phase Conjugate

Based on the phase conjugate technique,a real-time measurement technique was proposed to test the diffraction of the dynamic volume holograms.In the optical system,the object wave and the reference wave are adjusted much stronger than the probe beam propagating along the counter-direction of the reference wave (this phase-conjugate probe beam is about 1/1 000 of the reference beam).Thus the real-time and non-destructive testing of the dynamic holograms can be obtained by measuring the phase-conjugate wave of the object wave,which overcomes the readout erasing effect compared to the conventional technique by directly reading holograms with the reference beam via blocking object beam from time to time.Since the intensity and the polarization of each beam can be adjusted and combined among them by using the quarter-wave plate,polarizer and attenuator,the intensity-modulation or polarization-modulation volume hologram can respectively be recorded and tested.This technique fits for the photorefractive or photochromic holographic materials.