Abstract

Use of the optical Doppler shift of laser light scattered from small particles as a noninterfering means of measuring instantaneous local fluid velocities has revolutionized flow measurement technology. Early laser velocimeters were essentially modified interferometers suitable for use only under laboratory conditions. Continued improvements in optical design have led to less sensitive configurations applicable to industrial environments. Optimum optical design for a given measurement task requires recognition of several interrelated and sometimes subtle factors including the unique nature of Gaussian laser beam propagation.

© 1976 Optical Society of America