Two-Fiber-Optic Method of Laser Doppler Velocimetry

The figure depicts the basic optical layouts for (1) conventional laser Doppler velocimetry (LDV) and (2) a newer method of LDV based partly on the use of two optical fibers. Whereas conventional LDV involves the use of at least two lasers aimed in specified direction and detection of light scattered to one detector in almost any direction, the newer method involves only one laser and fiber-optic receptors that collected light scattered in two specified directions.