中红外室温大能量Fe^(2+)∶ZnSe激光器

Mid-Infrared High Energy Fe^(2+)∶ZnSe Laser at Room Temperature

理论分析了室温条件下掺铁硒化锌(Fe^(2+)∶ZnSe)激光横向寄生振荡特性,结果显示通过减小抽运光斑尺寸可有效提升寄生振荡反转粒子数阈值,从而抑制Fe^(2+)∶ZnSe激光横向寄生振荡。以非链式脉冲氟化氢(HF)激光器为抽运源,搭建了Fe^(2+)∶ZnSe激光器实验装置,通过插入不同孔径的光阑,实验研究了不同抽运光斑尺寸下的Fe^(2+)∶ZnSe激光输出特性。实验结果表明,对于端面尺寸为20 mm×20 mm的Fe^(2+)∶ZnSe激光晶体,当抽运光斑尺寸≤9.2 mm时,横向寄生振荡现象可得到有效抑制,与理论分析结果相符。室温条件下,所获得的最高Fe^(2+)∶ZnSe激光脉冲能量为136 mJ,斜效率为33.2%,相对于抽运激光能量的光-光转换效率为26.5%。

The transversal parasitic oscillation characteristics of Fe^2＋ ：ZnSe laser operating at room temperature are theoretically analyzed, and the results show that the population inversion threshold of parasitic oscillation can be effectively increased via the decrease of pump spot size, and thus the transversal parasitic oscillation of Fe^2＋ ： ZnSe laser can be effectively suppressed. The experimental setup of Fe^2＋ ： ZnSe laser end-pumped by a non-chain pulsed hydrogen fluoride （HF） laser is established. By inserting irises with different apertures, the output characteristics of Fe^2＋ ：ZnSe laser are experimentally studied under different pump spot diameters. The experimental results show that, as for a Fe^2＋ ： ZnSe crystal with end size of 20 mm × 20 mm, the phenomenon of transversal parasitic oscillation can be effectively suppressed when the pump spot diameter is smaller than 9.2 mm, which is consistent with the theoretical analysis result. At room temperature, the maximum Fe^2＋ ： ZnSe laser pulse energy that one can obtain is 136 mJ, the slope efficiency is 33.2%, and the optical to optical efficiency is 26.5% relative to the pump light energy.