光电探测器是相干激光多普勒测速仪的重要组成部分,其对光信号强度的响应特性直接影响着系统的信噪比。为了提高系统探测性能,从光电探测器非线性响应对相干激光多普勒测速仪的影响的角度进行研究。通过对响应函数进行多项式分析,研究输入拍频信号为带偏置的余弦信号时的输出电压波形,对比分析存在二阶非线性响应与在线性响应下的信号,从理论上说明探测器非线性响应对系统信噪比的影响。并对测速仪进行了对比实验,在对非线性响应进行抑制之后,系统信噪比由16dB提高到35dB,从实验角度验证了分析的正确性。 Photoelectric detector is an important part of the coherent laser Doppler velocimeter, and its response to the optical signal intensity directly affects the signal to noise ratio of the system. In order to improve the detection performance of the system, the influence of the nonlinear response of the photodetector on the coherent laser Doppler velocimeter is studied. Through the polynomial analysis of the response function, the output voltage waveform when the beat signal is input as the cosine signal with bias is studied. The second order non-linear response and the signal under the linear response are comparatively analyzed. It is theoretically proved that the detector nonlinearity Response to the system’s signal to noise ratio. The speedometer is compared with the experimental one. After suppressing the nonlinear response, the signal-to-noise ratio of the system is increased from 16dB to 35dB. The experimental results verify the correctness of the analysis.