We describe a new method for angular displacement measurements that is based on a Fabry-Perot interferometer. A measurement accuracy of 10^(-8) rad is obtained by use of the sinusoidal phase modulating interferometry. Another Fabry-Perot interferometer is used to obtain the key initial angle of incidence.
© 2005 Chinese Optics Letters
Caini Zhang and Xiangzhao Wang, "A new method for angular displacement measurement," Chin. Opt. Lett. 1, 459-461 (2003)