自带计量标准器的二维位移工作台研究

Study of 2D displacement platform with measurement standard instrument

提出以平面正交衍射光栅作为二维位移工作台计量标准器的方法 ,随工作台的移动 ,光栅能同时检测一个平面上两个方向的位移 .阐述了正交衍射光栅作为位置检测元件的工作原理及其光路布置方法 ,二次衍射光线的两两迭加 ,形成两组干涉条纹信号 ,且这两组干涉条纹信号的相移与光栅两个正交方向的位移呈正比 ,通过光电转换和计数细分处理电路得到条纹信号的相移 ;检测光路布置在工作台下方 ,通过几组直角棱镜使干涉条纹信号进入光电探测器 .实验分析了工作台的测量精度 ,有效分辨率提高到 1 0nm .

A method was presented that plane cross diffraction grating is taken as measurement standard sensor of 2D displacement platform. The grating can get displacement of two directions in one time with the motion of platform. The work principle of cross diffraction grating for displacement measurement was explained and the whole light-route structure was arranged. The two groups of interference strips signals formed by overlap-add of two second -diffraction lights of two vertical direction respectively, and each phase shift was proportion to the displacement of its direction. The phase shift can be gained by photoelectric conversion and circuit process of counter and subdivision. The measurement light-route was placed below the platform and the strip enter detectors by a few groups of square prism. The measurement precision of the platform was analyzed by the experiment and the effective resolution was less than 10?nm.