基于金刚石拉曼转换的光束亮度增强研究进展

具有不同波长的高亮度激光在国防、工业、生命科学等诸多领域发挥着重要作用。但是受限于现有工作物质固有的光谱特性和热物性,传统粒子数反转激光器的波长和输出功率难以兼顾,甚至导致激光在功率提升时光束亮度不升反降。为了克服该难题,近几年人们利用非线性光学技术对光束净化开展了大量研究,即将粒子数反转激光器输出的低光束质量的光束,通过受激拉曼或受激布里渊散射等效应转变为高光束质量激光输出。其中,金刚石晶体以其高拉曼增益系数、极高的热导率和极宽的光谱透过范围等性质,在实现高效率拉曼波长转换的同时展现出优异的光束亮度增强特性,为人们获得高功率、高亮度激光光束提供了新的技术路径。文中对基于金刚石的一阶和级联拉曼转换的光束亮度增强研究进行了综述,并围绕其潜在的应用进行了探讨。

Development of beam brightness enhancement based on diamond Raman conversion

High brightness laser sources with different wavelengths play an important role in the fields such as defense, industrial, and life sciences etc. However, due to the intrinsic spectral and thermophysical properties of current available laser gain materials, it is difficult to take into account the wavelength and output power of the traditional inversion lasers, which even leads to the decrease of beam brightness. To overcome this problem, beam cleanup by using nonlinear optical technology has been carried out in recent years, which is directly transferring the low beam quality generated from inversion lasers into the high through the effects such as stimulated Raman or Brillouin scattering. Among them, with excellent properties such as high Raman gain coefficient, high thermal conductivity and wide spectral transmission range, diamond exhibits excellent beam brightness enhancement characteristics while realizing high efficiency Raman conversion, which provides a new technical path to generate high power and high brightness laser beam. Here, the development of brightness enhancement based on first-order and cascaded Raman conversion of diamond was reviewed, and its future applications were discussed.