Laser Tracking Measurement System Based on Dual-Femtosecond Optical Frequency Comb

Abstract

Laser trackers are one of the most commonly used large-scale measurement systems in the fields of aircraft inspection, shipbuilding, automobile assembly, and other manufacturing sectors. Using a laser tracker can enable an operator to obtain an object’s spatial position through a combination of distance measurement and angle measurement. To realize distance measurement, traditional laser trackers use interferometry or phase ranging, each of which has its own strengths and weaknesses. Interferometry can achieve high-accuracy and high-frequency distance measurement, but it can only determine relative distances. Phase ranging can implement absolute distance measurement, however, its measuring frequency is limited due to its measuring principle. In this article a novel laser tracking measurement system is presented which realized high-frequency absolute distance measurement using a dual-femtosecond optical frequency comb with the accuracy of 0.5 ppm. We first introduce the measuring principle and overall design of the system.