Ultra-precision angle sensor with a mode-locked laser source

Abstract

This paper presents a new optical angle sensor, in which a mode-locked laser referred to as an optical frequency comb is employed as the light source. Highly-stable carrier frequency of the optical frequency comb is expected to improve the sensor stability. This angle sensor is designed based on laser autocollimation method, and utilizes the chromatic dispersion of an objective lens to detect angular displacement of a measurement target. A detail of the proposed method is described, followed by some experimental results with the developed prototype optical sensor.