新型实用高精度Talbot－Moire测焦法研究

NOVEL PRACTICAL AND ACCURATE METHOD OF MEASURING FOCAL-LENGTH WITH TALBOT-MOIRE TECHNIQUE

本文首先从理论上证明了用单色平面波照射光栅时，在透镜后形成的Ｔａｌｂｏｔ－Ｍｏｉｒｅ象关于焦点的对称性．并利用这种性质提出了一种测量透镜焦距的方法，该方法采用光栅莫尔技术找准对称象的位置，再经简单计算得到透镜焦距．理论分析和实测研究表明此方法方便实用，对被测焦距的长短没有要求，而且容易实现高精度的测量．

The property that the Talbot-Moire image behind lens is symmetry to focal point when monochromatic light illuminate grate is proved theoretically. On the base of above, a method of measuring focal-length, in which the symmetrical image position with which the focal-length is worked out simple is found with moire technique, is demonstrated. The theoretical analyse and experimental result show this method is convenient and practical and can be adapted to all focal-length. Furthermore, high precise focal-length measuring can be achieved with this method easily.