Abstract
Currently available nonperturbative flow velocity measurement techniques include such methods as laser Doppler velocimetry, fluorescence line shape detection,1 flow-marking methods,2 and schlieren. These techniques yield flow velocities in a wide range of environments. Below we describe a two-beam coupling induced- grating technique that we have demonstrated in a flowing liquid cell. Other grating techniques have been demonstrated,3,4 but they do not use the simple two-beam arrangement. Our method has a number of useful properties: (1) it allows rapid velocity measurement with minimal postprocessing; (2) it can operate in an unseeded absorbing environment or with an atomic or molecular seed; (3) it is self-normalizing; that is, two measurements are made and their ratio is taken, so that troublesome quantities, such as beam misalignment, cancel out of the result; (4) it also yields the sign of the relevant velocity component; (5) it can be performed with a single cw laser and simple apparatus; (6) it appears to operate best at subsonic velocities and may be scalable to higher velocities; and (7) it can be performed with several beams to yield all three components (including signs) of the velocity simultaneously.
© 1990 Optical Society of America
PDF ArticleMore Like This
Mark G. Allen, William J. Kessler, and Steven J. Davis
FC3 OSA Annual Meeting (FIO) 1990
Anno Hermanns, Diana M. Lininger, Claus Benkert, and Dana Z. Anderson
ThMM1 OSA Annual Meeting (FIO) 1990
Doron Chomsky, Sternklar, Henrik Szichman, and Steven Jackel
FI4 OSA Annual Meeting (FIO) 1990