Progress in laser Doppler velocity measurement techniques

This paper gives a review of the latest advances in laser Doppler velocity measurement techniques.A brief introduction of the principle of laser Doppler velocity measurement techniques is given in the beginning,then the structures,principles,advantages and disadvantages of several classical laser Doppler velocimeters,including differential mixing and other six kinds of single-frequency laser Doppler velocimeters and orthogonally polarized dual-frequency laser Doppler velocimeters,are discussed in detail.Besides that,this paper gives a comprehensive introduction of HH type dual-frequency laser Doppler velocimeter which is developed by Tsinghua University recently to increase the measurable range significantly.The development trend of laser Doppler velocity measurement techniques is also discussed at the end.