衍射相关和Lau干涉

本文用离轴傅里叶变换系统的模型和菲涅耳衍射理论分析了衍射受限下的离焦相关器的系统特性,证明是第一模板和第二模板衍射像之间的强度相关积分。推导了衍射相关器作为测量相位物体的干涉仪的一般理论,这时要求编码板函数能衍射自成像并且相关函数为周期性函数。讨论了平行光栅作为编码板时的干涉仪的横向剪切干涉特性,给出了实验结果。本文还证明了衍射相关器是推广到任何平面物体在任何观察距离上的Lau效应装置。衍射相关干涉仪产生Lau干涉条纹,并且是直接应用Lau效应的干涉仪。 关键词：

DIFFRACTION CRRELATION AND LAU INTERFEROMETRY

The operation of diffraction-limited misfocused correlator is analysed in terms of a model of off-axis optical Fourier-transformation system and the theory of Fresnel diffraction. It is proven that correlation still remains but between the intensity transmittance of the first transparency and the intensity diffraction pattern, of the second. The diffraction correlator can be modified as an interferometer, a general theory is deduced for it. The interferometry using two Ronchi gratings is discussed in detail, that yields lateral shearing interferogram, some corresponding experiment results are also given.It can be seen that the diffraction correlator is the setup of Lau effect for any plane objects and for any observating distance. Thus its application for interferometry is just as the interferometer directly based on the Lau effect.