绝对测温转动拉曼激光雷达分光系统设计及性能  

Design and performance of spectroscopic filter of rotational Raman temperature lidar for absolute measurement

作　　者：李启蒙[1] 李仕春[1] 秦宇丽 胡向龙 赵静 宋跃辉[1] 华灯鑫[1] 

机构地区：[1]西安理工大学机械与精密仪器工程学院,西安710048

出　　处：《物理学报》2018年第1期132-141,共10页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:61308106;41627807)资助的课题~~

摘　　要：为实现转动拉曼激光雷达的绝对测量温度技术,设计并测试了多通道转动拉曼分光系统.提出了一阶闪耀光栅与光纤Bragg光栅组成的两级并行多通道拉曼分光系统,优化了其核心级联器件(微米级光纤阵列)的参数及光路结构;仿真分析了一级分光系统的分光光路,转动拉曼谱线最大离心伸缩量约为0.0031 nm,离心伸缩比为0.69%;实验测试表明一级分光系统各转动拉曼通道的通道系数均在0.75以上,提取到拉曼光谱的实测中心波长与理论值的最大偏差约为0.0398 nm,偏离度为8.86%,可提供对弹性散射信号27 dB以上的有效抑制,结合已有光纤Bragg光栅二级分光实现高达62 dB弹性散射的抑制效果,可以实现对单条偶转动量子数转动拉曼谱线的精细光谱提取.Rotational Raman temperature lidar for absolute measurement is an important method to directly detect the atmospheric temperature profile by using active remote sensing technology. Compared with the rotational Raman temperature relative measurement, the absolute measurement can avoid the systematic error caused by the calibration process, but its high-precision requirements of rotational Raman spectroscopic filter restrict the development of absolute measurement technique for atmosphere temperature. In order to achieve the absolute measurement technique of rotational Raman temperature lidar, the fine resolution of single rotational Raman line and the effective suppression 60–70 d B for the elastic scattering signal are the key factors for directly retrieving the atmospheric temperature by using the relationship between the single rotational Raman line and temperature. Based on the operational principle of grating, a two-stage parallel multi-channel Raman spectroscopic filter with one-order blazed grating and fiber Bragg grating is designed, and the parameters and optical path structure of the core cascade device（micron-level fiber array） are optimized. The optical path of the primary spectroscope is simulated, the wavelength difference between the rotational Raman lines of adjacent even rotational quantum numbers of nitrogen molecule（N2） gradually decreases from 0.4506 nm to 0.4475 nm. Compared with the average of approximately 0.4494 nm, its floating interval is-0.0012–＋0.0019 nm, and the maximum centrifugal distortion of the rotational Raman spectra is approximately 0.0031 nm, which means that the centrifugal distortion ratio is 0.69%. Under the different values of incident angle φ, the diffraction position difference between adjacent rotational Raman lines varies from 124.43 μm to 125.51 μm, with a variation interval of-0.57–＋0.51 μm compared with a fixed value of 125 μm. In order to test the matching consistency between rotational Raman spectra and the multi-channel fiber array, and to

关 键 词：测温激光雷达 转动拉曼光谱 一阶闪耀光栅 多通道光纤阵列 

分 类 号：TN958.98[电子电信—信号与信息处理]