深紫外非线性晶体KBe_2BO_3F_2的倍频转换效率

Conversion Efficiency Properties by Second Harmonic Generation for Deep-ultraviolet Nonlinear KBe_2BO_3F_2

深紫外(DUV)相干光源对于光刻技术、激光微加工、激光光谱仪等均具有重要的意义。KBe2BO3F2(KBBF)晶体是目前唯一可直接倍频产生深紫外激光的非线性光学晶体。本文通过分析KBBF晶体的光学倍频特性,分别得到了Nd:YVO4激光2倍频、4倍频和6倍频以及Ti:Sapphire激光4倍频输出的相关技术参数;在此基础上,详细分析了KBBF晶体用于高斯光束的I类和II类倍频的转换效率。结果对于KBBF晶体用于产生深紫外全固态激光(DPL)的实验研究提供了重要的理论依据。

Coherent light sources in the Deep Ultraviolet （DUV） spectral regions become more important with the development of photolithography, laser micro-machining as well as laser spectroscopy. KBe2BO3F2 （KBBF） is now the only crystal to produce deep-UV coherent light just by using Second Harmonic Generation （SHG）. The technical parameter of the SHG, Fourth Harmonic Generation （FHG） and sixth harmonic generation using the Nd：YVO4 laser and the FHG using the Ti：Sapphire laser are obtained according to the frequency doubling in KBBF. The theoretical conversion efficiency of the Gaussian beams was obtained by using the numerical simulation on the crystal KBBF in the matching type Ⅰ and type Ⅱ for the first time. These academic results are very useful in DUV-DPL experimental studies.