小型化高光束质量MgO:PPLN中红外光参量振荡器

Miniaturized mid-infrared MgO: PPLN optical parametric oscillator with high beam quality

为满足中红外激光的工程应用需求,研制了基于MgO:PPLN晶体的小型化高光束质量中红外光参量振荡器(MgO:PPLN-OPO)。泵浦源采用声光调Q Nd:YVO4激光器,通过泵浦MgO:PPLN晶体,获得了高效率、高峰值功率中红外激光输出,在MgO:PPLN-OPO谐振腔中加入光阑,有效提高了中红外激光光束质量,整个激光器采用热电制冷与风冷相结合的散热方式,实现了激光器的小型化。实验结果表明:采用无水冷的声光调Q Nd:YVO4激光器能够实现最高9.3 W的1.064μm脉冲激光输出,光光转换效率为27.2%,峰值功率可达~27.5 kW;在Nd:YVO4激光器泵浦下,MgO:PPLNOPO实现了3.765μm脉冲激光输出,在谐振腔中加入光阑后,MgO:PPLN-OPO的最高输出功率由1.20 W略降至1.08 W,但光束质量有明显提高,Mx2和My2因子分别从1.89和1.98优化至1.20和1.29,中红外激光脉冲宽度为8.4 ns,峰值功率达到~4.3 kW。

In order to meet the engineering application of mid-infrared laser,a miniaturized mid-infrared MgO:PPLN optical parametric oscillator(MgO:PPLN-OPO)with high beam quality was presented.The pump source was an acousto-optical Q-switched Nd:YVO4 laser.By pumping the MgO:PPLN crystal,the mid-infrared laser with high efficiency and high peak power was obtained.And the mid-infrared beam quality was improved by adding an aperture in the cavity.The whole laser was cooled by thermoelectric cooling and air cooling.Therefore,the size of the laser was miniaturized.Experimental results indicate that the acousto-optical Q-switched Nd:YVO4 laser can realize the pulse laser with the highest power of 9.3 W at 1.064μm.The corresponding optical to optical conversion efficiency is 27.2%and the peak power is^27.5 kW.With the Nd:YVO4 laser pump,the MgO:PPLN-OPO can output the pulse laser at 3.765μm.When adding the aperture in the cavity,the maximum output power of the MgO:PPLN-OPO decreases from 1.20 W to 1.08 W.However,the beam quality improves obviously.The Mx2 and My2 factors change from 1.89 and 1.98 to 1.20 and 1.29,respectively.The pulse width and the peak power of mid-infrared laser are 8.4 ns and^4.3 kW,respectively.