A Laser Interferometric System for Measuring Arbritrary Angles

Abstract A laser interferometric system for measuring arbitrary angles has been developed. The system comprises a two-stage precise rotary table, an adjustable optical polygon, a laser interferometer for measuring constant angles, a frequency optically six-multiplied differential laser Interferometer for measuring small angles, and a CCD-microcomputer-based interferometric signal processing system. The Interference phenomena occuring in the cases of different constant angles with differently oriented incident beams, the method of angle tracking and the method of determining the equivalent parameters of the laser interferometer for measuring small angles are discussed in this paper. Experiments show that this system gives an accuracy better than 0.3 arcseconds in measuring arbitrary angles ranging from 0 to 360 degrees. High accuracy, self-calibration ability, new measuring principles, convenience in use, and low cost are the distinguishing features of this system.