Frequency shift error of AOM in Doppler lidar system

The accurate value of speed measurement can be influenced by the errors of frequency shift of acousto-optic modulator in Doppler lidar system. The fixed frequency shift through reciprocity between acoustic field and optical frequency in acousto-optic modulator was researched by the method of self heterodyne to analyse the frequency shift error of acousto-optic modulator in Doppler lidar system. The result of frequency shift error from acousto-optic was studied under the condition of different but stationary acoustic field driver frequency by the way of statistics. The experiment results indicate that the frequency shift error in acousto-optic modulator is less than 0.61 MHz in Doppler lidar system, it means that the error of Doppler speed measurement is less than 0.3 m/s when the wavelength is 1 064 nm. The analysis of frequency shift error can provide references for error analysis of high precision Doppler lidar system.