Multibeam operation of a YAG:Nd3+ laser and its use in laser anemometry

Multibeam (with up to 12–14 beams) single-mode operation of a YAG:Nd³⁺ laser with conversion of the 1.06 μ radiation to the second harmonic at 0.53 μ was investigated. A comparison was made of the parameters of the usually employed differential, and multibeam system in which a measuring zone is created by intersection of n identical laser beams. A considerable improvement in the sensitivity and an increase in the period of the selected signals were exhibited by an n-beam optical system because of the n-beam interference. The use of a multibeam YAG:Nd³⁺ laser in laser anemometry made it possible to combine successfully the advantages of differential and time-of-flight schemes, which thus extended their capabilities.