利用联合付里叶变换谱干涉法测量透镜焦距

Focal length measurement of spherical lens using joint Fourier transform spectrum interference technique

本文提出了采用联合付里叶变换频谱干涉法测量透镜焦距的方法。输入面上两个分布完全相同的图像经光学付里叶变换在频谱面上得到二者付里叶变换频谱的干涉条纹，通过测量干涉条纹的间距即可得到透镜的焦距。该方法装置简单、操作调整方便；易于采用实时空间光调制器、ＣＣＤ及微机实现快速自动测量，且具有较高的精度。文中进行了原理分析和实验验证。

A method for testing meonochromatic focal length of spherical lens using joint Fourier transform spectrum interference technique is given in this paper. Two identical images of certain separation are Fourier transformed at the same time by the tested lens, and the interference fringes are formed at its back focal plane (the spectrum plane). The focal length is calculated by measuring the interference fringe spacing. The system is simple and convenient to adjust. By using real time spatial light modulator, CCD, and computer, automatic and fast measurement of focal length can be realized with reliable results.