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

在这项研究中，开发了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。研制了小型光学参量振荡器，在1.5~1.93μm和2.36~3.68μm波长范围内，获得了脉宽20 ns、重复频率1~10 kHz、光谱宽度175 MHz、平均功率10~150 mW、单频稳定的可调谐红外脉冲光束。利用长程吸收激光雷达，利用150m距离、信噪比为100、吸收精度为10~(-2)&GT的粗糙表面目标测量了大气甲烷。在1s的积分时间内，可以通过提高激光效率和降低系统噪声来进一步改善系统特性，以实现预计的理想性能。该传感器系统的应用范围包括：1)在交通负荷、工厂、机场和市区上空使用合适的目标测量广域分子密度和空间综合高度分布；2)基于紧凑型汽车和飞机的新型移动系统可能在更高的脉冲能量模式下测量全球空气污染的传输特征和大气环境属性

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