The recently reported multiple line laser Doppler velocimetry technique involves a compromise between laser power and fringe broadening. The present work analyzes the broadening as a function of both the target velocity and the separations of the Fabry-Perot etalons, which in this work do not have to be the same. It is shown that the overlap finesse broadening, which is defined as the ratio of the frequency separation between fringes to the overlap broadening, depends on the number of free spectral ranges that have occurred due to the velocity of the reflecting target.
© 1990 Optical Society of America
David R. Goosman, "Dynamic fringe broadening in multiple line laser Doppler velocimetry," Appl. Opt. 29, 107-110 (1990)