In order to improve the measurement accuracy and the real-time performance in long absolute distance measurement, a method based on high stability and synchronization multi-frequency is proposed. Multi-frequency is generated by shifting one mode laser frequency with three acousto-optic frequency shifters, and couple in one beam by fiber. Heterodyne frequencies between different multi-frequency is separated by its different polarization and frequency bandwidth, and acted as the coarse and precision measuring frequency. Therefore synchronous occurrence of measuring multi-frequency is achieved, which improve the real-time performance of measurement. Results of the experiment show that the measuring frequency stability is better than 3.6×10-8, and the laser range finder have an uncertain measuring result of less than 60 μm at a distance of 20 m under laboratory conditions.

Date Published: 31 January 2013
PDF: 8 pages
Proc. SPIE 8759, Eighth International Symposium on Precision Engineering Measurement and Instrumentation, 87593N (31 January 2013); doi: 10.1117/12.2014566

Published in SPIE Proceedings Vol. 8759:
Eighth International Symposium on Precision Engineering Measurement and Instrumentation
Jie Lin, Editor(s)