高功率激光与“超热导”激光晶体

高功率固体激光技术的发展史就是一部与“废热”的斗争史,为抑制热效应对光束质量的不利影响,先后出现了热容激光器、薄片激光器、板条激光器以及光纤激光器,新的增益介质形态结合先进的散热技术将激光输出功率提升至百千瓦量级。固体激光增益介质的热学性能是限制激光功率进一步取得突破的重要瓶颈。因此,寻找具备超高热导率的激光晶体材料意义重大。本文介绍了上述四种激光器的基本原理及其在高功率激光方面取得的研究进展,从提高增益介质材料热导率的角度出发,对目前已有的方法和研究成果进行了分析与总结,对超热导激光晶体研究和高功率激光技术的发展进行了展望。

High-Power Laser and Ultra-High Thermal Conductivity Laser Crystals

The development of high-power solid state laser technology is a course of struggling against the "waste heat" generated with lasering. The most critical issue for the development of high-power solid-state lasers is how to suppress the thermal effect on the beam quality under high-power operating conditions. To improve this adverse effect researchers invented heat capacity laser, thin-film laser, slab laser and fiber laser. These new designs of lasers based on novel form of gain medium combined with advanced heat dissipation technology have enhanced the output power to about one hundred kilowatts. However, the thermal properties of the solid state gain medium have become the critical bottleneck restricting further breakthroughs in laser power. Therefore, it is of great significance to explore the novel laser crystal materials with ultra-high thermal conductivity. This paper introduces the basic principles of the above four lasers and their research progress in high-power lasers. From the perspective of improving the thermal conductivity of gain medium materials, the existing methods and related results are analyzed and summarized. The research on ultra-high thermal conducting laser crystals and the development of high-power laser technology are also prospected.