Analysis of Signal-to-Noise Ratio of the Laser Doppler Velocimeter

The signal-to-shot-noise ratio of the photocurrent of a laser Doppler anemometer is calculated as a function of the parameters which describe the system. It is found that the S/N is generally a growing function of receiver area, that few large particles are better than many small ones, and that generally the "fringe" or l"differential" mode configuration is equal to, or better than, the "reference beam" mode.