WIDE-RANGE DISTANCE METER BASED ION FREQUENCY-MODULATION OF AN ND-YAGLASER

The paper presents a distance meter for noncontact measurement over ex tended 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 ra nge from 1 to 11 m. In accordance with the state of the art of the FMC W 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 behavio r of the optical frequency modulator. (C) 1996 Society of Photo-Optica l Instrumentation Engineers.