甲烷和氢气混合气体中的多波长拉曼转换

探索Nd：YAG倍频激光与受激拉曼散射(SRS)结合获得从紫外到可见光范围的多波长输出，可应用于激光雷达探测空气污染等领域。利用Nd：YAG激光的三倍频355nm波长输出在甲烷及甲烷和氢气混合气体中的拉曼特性进行研究。获得在396nm，416nm，447nm和503nm 515nm等多个波长分别约100mW的同时输出，以及对个别波长的增强。讨论了不同常见的工作气体及混合气体的特点。与单一工作气体(氢气或甲烷)相比，混合气体可以获得更为丰富的波长输出。相比甲烷气体在紫外激光照射下的分解作用，由于氢气的加入一定程度上抑制了分解反应，混合气体产生的分解沉淀较少。

Multi-Wavelength Raman Frequency Conversion in the Mixture of CH4 and H2

A combinative technology of triple-frequency solid laser and SRS has been investigated to obtain multi-wavelength laser lines covering waveband from ultraviolet to visible. This technology could be applied in LIDAR such as measurement of air pollution. The SRS characteristics have been studied pumped by a triple-frequency Nd∶YAG laser in methane and a mixture gas of methane and hydrogen. Multiple wavelength lines were obtained simultaneously at 396 nm, 416 nm, 447 nm and 503 nm+515 nm with output power about 100 mW for each line. The characteristics of the most familiar Raman gases and a mixture gas of methane and hydrogen were also discussed. Comparing with the individual gas (methane or hydrogen), more abundant lines have been obtained in the mixture gas. Unlike strong decomposition in methane irradiated by UV laser, the decomposition was restrained by adding hydrogen in the mixture gas.