Multi-channel laser interferometer based on automatic frequency stabilization system for improving coordinate measurement accuracy

A multi-channel laser interferometer (MCLI) is proposed to improve the coordinate measurement accuracy. A 780 nm external cavity laser is locked on the D₂ line of ⁸⁷Rb atom by polarization spectroscopy, and a high frequency stabilized laser source is obtained with a linewidth of 385.8 kHz at root mean square (RMS). The interferometers share the stabilized source and individually install on 4 axes of a coordinate measuring system. As a result, the measurement uncertainty is reduced from 1.2 µm to 0.2 µm within the dynamic measurement range of 1.0 m. The MCLI is adept at integrate and flexible installation, which caters to various applications on precision measurement.