Chinese Optics Letters, Vol. 2, Issue 9, 09520 (2004)
Position sensor based on slit imaging
Aijun Zeng, Xiangzhao Wang, Yang Bu, and Dailin Li
- Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800
A position sensor based on slit imaging is proposed and its measurement principle is described. An imaging slit is illuminated by a collimated laser beam with square-wave modulation and imaged on a detection double slit through a 4f system. A magnified image of the detection double slit is formed on a bi-cell detector. The position of the imaging slit is obtained by detecting light intensity on two parts of the bi-cell detector. In experiments, the feasibility of the sensor was verified. The repeatability was less than 40 nm.