Abstract
This paper presents a compact and high-sensitive angle sensor suitable for measurement of stage angular motions, such as pitching and yawing. The compact angle sensor is based on laser autocollimation for angle detection. To maintain the high sensitivity while miniaturizing the sensor size, the relationship between the spot size on the focal plane of the objective lens and the output of the photodetector with separate elements (bi-cell PD and quadrant PD) is analyzed with wave optics. A compact sensor is also developed based on the analysis result. Experiments have shown that the compact sensor has a resolution of 0.01 arc-seconds.
