Frequency-modulated continuous-wave laser distance measurement system using Fabry- Perot cavity as measuring reference
Abstract
Frequency-modulated continuous-wave (FMCW) is a ranging technique that allows for high precision distance measurement over long distances. Scanning nonlinearity and range of the tunable laser are the main factors affecting the measurement accuracy. Frequency-sampling method is a recognized post-processing scheme to compensate the scanning nonlinearity. In this work, an FMCW laser distance measurement system using a high fineness Fabry-Perot (F-P) cavity as a sampling reference is demonstrated. The frequency of the resampled signal is calculated with a Hilbert transform. The high stability of the F-P cavity and the advantages of the Hilbert transform lead to a high measurement precision when an external cavity diode laser (ECDL) with a scanning range of tens of GHz is available. In this experiment, the scanning range of the ECDL is only 88 GHz, and a measurement uncertainty of 76.8 um (with coverage factor of k = 2) within a distance of 6.7 m is demonstrated.
Keywords
Cite
@article{arxiv.1901.01131,
title = {Frequency-modulated continuous-wave laser distance measurement system using Fabry- Perot cavity as measuring reference},
author = {Guang Shi and Kefei Hei and Wen Wang and Nandini Bhattacharya},
journal= {arXiv preprint arXiv:1901.01131},
year = {2019}
}