与目前广泛应用的532 nm波段的发射波长相比, 采用355 nm波段发射波长进行大气温度观测对分光光谱仪的精度要求更高, 分光光谱仪的线色散率要达到0.1 nm/mm。提出了一种新型高线色散率纯转动拉曼激光雷达分光光谱仪, 通过设计双光栅结构来达到激光雷达纯转动拉曼回波信号分光的目的。利用Zemax软件进行设计, 模拟分析结果显示：间隔0.1 nm的两个相邻光谱在分光光谱仪聚焦镜焦平面处两个相邻谱线中心可以分开1 mm, 满足测温纯转动拉曼分光光谱仪线色散率达到0.1 nm/mm的要求。将实验得到的斯托克斯回波信号强度与理论计算结果进行对比, 验证了纯转动拉曼雷达中应用双光栅光谱仪的可行性。

Compared with the widely used emission wavelength of 532 nm, the atmospheric temperature observation using the emission wavelength of 355 nm requires higher precision of the spectroscopic spectrometer, and the line dispersion rate of the spectroscopic spectrometer should reach 0.1 nm/mm. A new high linear dispersion pure rotational Raman laser lidar spectrophotometer is proposed, which uses the double grating structure to achieve the purpose of laser lidar pure rotational Raman echo signal separation. Zemax software is used to design, simulation results show that the interval of 0.1 nm in two adjacent spectrum spectral optical system focus lens focal plane in the center of two adjacent line can be separated from 1 mm, which satisfies the requirement of line dispersion rate of temperature measuring pure rotational Raman spectroscopic spectrometer to reach 0.1 nm/mm. Comparing the experimental Stokes echo signal strength with theoretical calculation, the feasibility of the double grating spectrometer in the pure rotational Raman lidar is verified.