【摘要】 基于大气激光后向散射光谱,研究和设计了探测大气CO₂浓度的Raman激光雷达,其发射机采用Nd∶YAG激光的三倍频354·7nm作为工作波长,发射的单脉冲能量350mJ,重复频率20Hz;接收机采用了光电倍增管（量子效率25%）和光子计数器（计数速率200MHz）,探测CO₂的Raman散射371·66nm（频移1285cm-1）信号,（1小时累加）近地面2·5km以内信噪比不小于8.采用组合滤光片来抑制强的354·7nm Mie-Rayleigh后向散射和氧气375·4nm Raman后向散射对信号的严重干扰.比较分别来自大气CO₂和参考气体N₂的Raman后向散射回波,可反演出大气中CO₂的相对浓度.更多还原

【Abstract】 Based on laser atmosphere backscattering spectrum, the design and experiment of a Raman lidar system for measurement of atmospheric CO₂ are presented. 354.7nm third harmonic of Nd∶YAG laser is transmitted with 350mJ pulse energy and repetition rate of 20Hz. The receiver employs a photomultiplier tube with quantum efficiency of 25% and 200MHz photon counter, and it detects Raman backscattering 371.66nm（shift 1285cm -1 ） signal. At 1h integration, the signal to noise ratio below 2.5km is greater than 8. Combinatorial filter is used to reject interference presented by 354.7nm intense Mie-Rayleigh backscattering and 375.4nm Raman backscattering from O₂. We compare the Raman return signal at 371.66nm from atmospheric CO₂ with the reference Raman return signal at 386.7nm from atmospheric N₂ to retrieve the atmospheric CO₂ concentration.更多还原