用横向剪切干涉仪测量部分相干度

本文提出了用横向剪切干涉仪测量光的部分相干度的方法;用非相干光照明的圆孔作为实际光源,测量了不同剪切量的部分相干度,所得实验结果与理论计算一致。

Measurement of the Degree of Partial Coherence Using Lateral Shearing Interferometer

The measurement of the degree of partial coherence of a light beam using a lateral shearing interferometer consisting of a corner cube and a Kosters prism together with two wedge prisms is reported. In order to make temporal coherence effect negligible, a suitable narrow band interference filter has been used.A pinhole illuminated by a given incoherent circular light source is used as an object wavefront, and two sheared wavefronts are then obtained by moving the corner cube in combination with the Kosters prism. The signals of interference fringes produced by two sheared wavefronts are detected by a photomultiplier and the output from the photomultiplier is compared with a reference signal at a phase-sensitive detector. The visibility of the fringes, i. e., the degree of partial coherence is then obtained. Experimental results show that they are in fair agreement with what is given by theoretical treatment.