Research on heterodyne efficiency of laser Doppler velocimeter

Heterodyne efficiency is a very important factor in a laser Doppler velocimeter (LDV). Gaussian-Airy mode is put forward to analyze the heterodyne efficiency. And the calculate formulas and results of simulation of heterodyne efficiency are given. The results of numerical analysis show that heterodyne efficiency of LDV depends on the parameters—x0, A, θ and xa. Heterodyne efficiency can reach 81.45%, when x0 = 3.59, A = 5.04 and θ = xa = 0. At last, the antenna theorem of LDV is derived, and a defocused telescope system is used to adjust the waist's position and radius of the reference beam to match the signal beam.