Frequency conversion concepts for the efficient generation of high power 935 to 942-nm laser radiation
Frequency conversion concepts for the efficient generation of high power 935 to 942-nm laser radiation
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DOI：
10.1117/12.646263
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发表时间：
2006-02
期刊：
影响因子：
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通讯作者：
H. Rhee;T. Riesbeck-;F. Kallmeyer;S. Strohmaier;H. Eichler;R. Treichel-;K. Petermann
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文献类型：
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作者：
H. Rhee;T. Riesbeck-;F. Kallmeyer;S. Strohmaier;H. Eichler;R. Treichel-;K. Petermann
全球大气中水汽分布的三维测量大大提高了天气预报和气候模拟的可靠性。星载差分吸收激光雷达（DIAL）可以利用水汽的宽吸收谱中的合适吸收线来完成这一任务。由于不存在对其他分子吸收的干扰，因此935/936 nm、942/943 nm的范围是水蒸气DIAL的最优选波长范围。基于受激拉曼散射（SRS）和Ti：Sapphire的频率转换器与直接产生的混合石榴石激光器之间的比较显示了每个概念的有利特性，并有助于评估最合适的概念。用于高脉冲能量的拉曼频率转换器的发展集中在线性谐振腔的设计和使用拉曼材料作为基于拉曼四波混频的直接放大器的种子。此外，还研制了一台种子稳频脉冲钛宝石激光器，其输出脉冲能量高达22 mJ，注入种子在935.684nm的水汽吸收线上，光谱纯度高达99.9%。利用二极管泵浦的Nd掺杂的YGG和GSAG晶体可以直接产生水蒸气检测所需的935/936 nm和942/943 nm波长。第一次实验导致在942 nm波长下，在Q开关中的脉冲能量为18 mJ，在自由运行操作中的脉冲能量为86 mJ。
The three-dimensional measurement of the global water vapor distribution in the atmosphere considerably improves the reliability of the weather forecast and climate modeling. A spaceborne Differential Absorption Lidar (DIAL) is able to per-form this task by use of suitable absorption lines of the broad absorption spectrum of water vapor. Because no interference with the absorption of other molecules exists, the range of 935/936 nm, 942/943 nm are the most preferred wavelength ranges for a water vapor DIAL. The challenge is to develop a dedicated efficient high power laser source emitting at these wavelengths. The comparison between frequency converters based on stimulated Raman scattering (SRS) and Ti:Sapphire and the directly generated Mixed Garnet laser shows the favorable properties of each concept and helps to evaluate the most suitable concept. Development of Raman frequency converters for high pulse energies concentrates on linear resonator de-signs and seeding using the Raman material as a direct amplifier based on Raman four-wave-mixing. In addition a seeded and frequency stabilized pulsed Ti:Sapphire laser system with output pulses up to 22 mJ injection-seeded at the water vapor absorption line at 935.684 nm with a spectral purity up to 99.9 % has been developed. Direct generation of the wavelengths 935/936 nm and 942/943 nm required for water vapor detection is possible with diode-pumped, Nd-doped YGG- and GSAG-crystals. First experiments resulted in pulse energies of 18 mJ in Q-switched and 86 mJ in free-running operation at 942 nm wavelength.