The paper presents a distance meter for noncontact measurement over extended ranges based on the frequency-modulated continuous-wave (FMCW) technique. A tunable diode-pumped Nd:YAG laser is used to generate the chirp signal. The system has been characterized over a measurement range from 1 to 11 m. In accordance with the state of the art of the FMCW interferometry, the average measurement accuracy of the system is 10-4 of the measured distance. The behavior of the frequency modulator has been experimentally characterized. A suitable signal elaboration procedure has been implemented to compensate for the nonlinear behavior of the optical frequency modulator.
"Wide-range distance meter based on frequency modulation of an Nd:YAG laser," Optical Engineering 35(7), (1 July 1996). https://doi.org/10.1117/1.600628