Small-displacement sensing system based on multiple total internal reflections in heterodyne interferometry.
A small-displacement sensing system based on multiple total internal reflections in heterodyne interferometry is proposed. In this paper, a small displacement can be obtained only by measuring the variation in phase difference between s- and p-polarization states for the total internal reflection effect. In order to improve the sensitivity, we increase the number of total internal reflections by using a parallelogram prism. The theoretical resolution of the method is better than 0.417 nm. The method has some merits, e.g., high resolution, high sensitivity, and real-time measurement. Also, its feasibility is demonstrated.
Wang
Shinn-Fwu
SF
Department of Electronic Engineering, Ching Yun University, No. 229, Chien-Hsin Road, Jhongli City, Taoyuan 320, Taiwan. sfwang@cyu.edu.tw
Chiu
Ming-Hung
MH
Chen
Wei-Wu
WW
Kao
Fu-Hsi
FH
Chang
Rong-Seng
RS