Abstract

The accurate measurement of distance to a poorly reflecting surface is required in many industrial applications. These applications often involve a moving target having a wide variation in reflectivity. This paper describes a technique which uses a semiconductor laser system which electronically compensates for a wide dynamic range in the reflected signal and which is capable of rapid measurement in real time. The system is based on the fact that as the path length of a modulated laser beam is altered, there will be a corresponding phase shift in the received signal.

© 1985 Optical Society of America