The Fabry-Parot etalon can be widely used in the lidar for Doppler wind measurement and aerosol detection. Due to the very wide application of the FP etalon, the standard transmission curve of the F-P is a very important parameter. The general FP etalon measures the transmittance curve by tuning the wavelength of the laser source or tuning the angle of incident light. The FP etalon generally measures the transmittance curve of the etalon by tuning the wavelength of the laser source or use the frequency comb source. Moreover, the tuning of the wavelength and the angle of incident light are nonlinear, and the measurement accuracy is insufficient, and the frequency comb source is very expensive. This paper proposes a new method for testing the transmittance curve of a FP etalon using a similar frequency comb source. The whispering gallery mode is a typical similar frequency comb laser source which has multiple frequency components, but not equal intervals. The spacing of the frequency of the whispering gallery mode is not equal, but the spacing of the frequency can be determined. So, the transmittance curve of the FP etalon can be measured at one time. And the frequency interval and spectral range are tunable easily. This new method greatly reduces the cost of measuring transmission curve, improve measurement accuracy and effectiveness and has great theoretical and practical value.
A Vehicle-mounted Mie lidar is developed. The structure and data processing method of the lidar system are introduced. Based on the traditional Fernald method,the inverse astigmatic aerosol extinction coefficient is proposed by using the fixed scattering ratio method. Using the lidar system, the temporal and spatial distribution of aerosols over hefei was detected, and the extinction coefficient profile of aerosols in the vertical direction and the spatial distribution of aerosols in the 45° azimuth Angle were obtained, which is of great significance for the realization of large-scale aerosol detection.