目前中国科学技术大学车载激光雷达已经实现了对于15~60 km中性大气风场的夜间连续观测, 鉴于白天观测的信噪比受到背景光的限制, 因此, 设计了一种利用现有干涉滤光片结合固态FP 标准具的超窄带滤光器, 用于实现背景噪声的降低。提出了一种结合鉴频器参数确定FP最佳参数的方法, 得出了 FP 标准具的参数, 实现了带宽为8.4 pm、中心波长为354.73 nm、自由光谱间距为150 pm、峰值透过率高于0.67的滤光器, 将背景噪声降低到原来的十八分之一。 该滤光器有效提高了系统信噪比, 减小了风速误差, 同时计算了温度、角度变化对滤光器带宽、中心波长和透过率的影响, 设计了一种角度调谐的方法。实验结果与理论值具有较高的一致性。

The mobile lidar of USTC implements the continuous wind measurement in 15-60 km neutral atmosphere at night. Since the signal to noise radio was limited by background light during daytime operation, an ultra-narrow filter which combined an interference filter with a solid FP etalon was designed to reduce the background noise. An approach to solve the optimum parameters for the F-P etalon was proposed, based on the Frequency Discriminator, an etalon filter with bandwidth of 8.4 pm, center wavelength of 354.73 nm, free spectral range of 150 pm and peak transmission of 0.67 was achieved to decrease the background noise to one in eighteen. The improvement of SNR and velocity errors were simulated. The effect of temperature and tilting angle on bandwidth, center wavelength and transmissivity was calculated. A method of tuning by tilting angle was designed. The experiment result is highly uniform with the theoretical value.