Development of a compact solid-state laser sensor for detecting distributed, low-concentration widely environmental-pollution molecules

在本研究中，已开发出一种长路径吸收激光系统，作为与环境污染和全球变暖问题相关的低浓度大气分子的遥感器。研制了一种紧凑型光学参量振荡器（OPO），可在1.50 ~ 1.93μm和2.36 ~ 3.68μm波长范围内产生脉宽20 ns、重复频率1 × 10 kHz、谱宽175 MHz、平均功率10 × 150 mW的单频和稳频可调谐红外脉冲光束。利用长光程吸收激光雷达，在150 m距离上对粗糙表面地形目标进行了大气甲烷的测量，信噪比为100，积分时间为1 s时的吸收精度为10 μ s<-2>，通过提高激光效率和降低系统噪声，可以进一步改善系统特性，实现预期的理想性能。该传感器系统的应用领域包括：（1）利用合适的目标测量交通负荷、工厂、机场和城市区域的大面积分子密度和空间积分高度分布;（二）基于小型汽车和飞机的新的移动的系统有可能在更高的脉冲中测量全球空气污染的传输特性和大气环境特性能量模型

In this research, a long-path absorption laser system has been developed as a remote sensor of low-concentration atmospheric molecules related to environmental pollution and global warming issues. The compact optical parametric oscillator (OPO) has been constructed for generating tunable infrared pulse beam of 20ns pulse width, 1〜10kHz pulse repetition frequency, 175MHz spectral width, 10〜150mW average power with single and stabilized frequency in the wavelength range of 1.50〜1.93μm and 2.36〜3.68μm. Using the long-path absorption laser radar, the atmospheric methane has been measured using a rough-surface topographic target at 150m range with the signal-to-noise ratio of 100, and the absorption accuracy of 10^<-2> in 1s integration time.Further improvement is possible in the system characteristics by increasing the laser efficiency and reducing the system noise to realize estimated ideal performance. Other molecules such as CO_2 and N_2O are possible to be detected with this system scheme.Application field of this sensor system covers 1) measurement of wide-area molecular density and spatial integrated height distribution using proper targets over the traffic loads, factories, airports and urban area, 2) new mobile systems based on a compact car and airplane are possible to measure transport characteristics of global air pollution and atmospheric environmental properties In a higher pulse energy model