A coherent-optical time-of-flight range-finding technique is proposed which uses a simple inexpensive device. Target range is determined by modulating a laser diode's optical frequency and measuring the change in the phase of the light reflected back into the laser. Target velocity as well as range can be measured using this approach. The device is described, and experimental evidence is presented to show the feasibility of measuring distance with subcentimeter resolution over a 1.5-m range.
© 1986 Optical Society of America
Original Manuscript: December 2, 1985
Published: May 1, 1986
Glenn Beheim and Klaus Fritsch, "Range finding using frequency-modulated laser diode," Appl. Opt. 25, 1439-1442 (1986)