Study of heterodyne grating interferometer

• Main Authors: Hui-Yi Chen, 陳輝毓
• Other Authors: Ju-Yi Lee
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/46198644654249640003

碩士 === 國立中央大學 === 機械工程研究所 === 94 === A heterodyne interferometry for measurement of the in-plane displacement is proposed. The measurement system includes a heterodyne light source, a moving grating and a lock-in amplifier for phase measurement. The in-plane displacement means that the direction of the measuring object displacement and the direction of the measuring light beam become vertical relation each other. The phase variation, which resulted from the displacement of grating movement, is measured by the heterodyne interferometry, and it is converted into the small in-plane displacement. Proved by the present experiment, the measurement range is about 1 millimeter, and its resolution is about 1 picometer.This method has some advantages, such as high sensitivity, high accuracy and large measurement range. It can apply to sense the small displacement, localization of the platform with high-accuracy, and so on.