基于三级Fabry-Perot标准具的纯转动拉曼测温激光雷达

提出了新的纯转动拉曼测温雷达系统，即以种子激光注入锁定的Nd:YAG激光器为激发光源，采用基于三级Fabry-Perot(F-P)标准具的双通道分光结构代替双光栅单色仪结构.通过通道中宽带滤光片(带宽为7nm)及F-P标准具的组合使用，对532nm激发光的大气Mie-Rayleigh弹性回波散射抑制比可达10^-10,对量子数J=±6，J=±12的N₂纯转动拉曼散射光谱线接收带宽均小于10pm，因此能充分抑制大气背景辐射噪声及O₂纯转动拉曼谱线的干扰，从而实现了单谱线比反演温度，提高了探测精度，且可在白昼探测大气对流层温度.最后通过探空气球测得的对流层温度垂直分布逆向模拟了该系统双通道的Raman信号曲线，证实了该系统的可行性. 关键词： 拉曼激光雷达 纯转动拉曼散射 三级Fabry-Perot标准具 对流层

A pure rotational Raman-lidar based on three-stage Fabry-Perot etalons for monitoring atmospheric temperature

A new pure rotational Raman-lidar system for monitoring atmospheric temperature is presented. Instead of using the double grating monochromator, the system employs two high resolution spectral resolving channels,each of which is composed of a three-stage Fabry-Perot etalon combined with a filter with band width of 7nm. The transmitting light source is an injection-seeded Nd:YAG laser. This configuration can achieve a high rejection rate (10^-10) to Mie-Rayleigh elastic scattering (at 532nm wavelength)，and has an extremely narrow receiving bandwidth (less than 10pm) for pure rotation Raman scattering of N₂ with quantum numbers of ±6 and ±12 respectively. Therefore, the system effectively rejects the interference of background radiation and pure rotational Raman scattering of O₂, and the measurement of daytime tropospheric temperature from a single Raman spectral line intensity ratio using the lidar system is made possible because of the narrow receiving bandwidth. The temperature measurement precision of this Raman-lidar is improved at the same time. At last, two_channels signals were simulated by using balloon-based sounding temperature profile. The simulation demonstrated the feasibility of this lidar for atmospheric temperature profile measurement.