4-14μm中红外激光在军事、环境、生物和科研等领域有着重要的作用，为了满足激光雷达、光电对抗、激光消融和生物大分子动力学等应用，需要发展宽调谐高能量中红外参量激光技术。但受限于非线性晶体的损伤阈值和透光范围，以及中红外泵浦光源性能和参量转换效率等问题，目前中红外参量激光能量较低、调谐范围有限。本项目采用自主生长的新型激光晶体，研制高光束质量的LD泵浦2.79μm电光调Q铒激光源，设计新型中红外非线性晶体BaGa4Se7（BGSe）的光参量振荡器，实现4-14μm超宽调谐高能量中红外激光输出。重点研究BGSe晶体宽调谐非线性特性，探索BGSe-OPO参量振荡机理，给出相位失配、走离效应、波长调谐及增益带宽变化与参量腔结构参数和泵浦参数的特性关系，建立高能量宽调谐BGSe-OPO的增益理论模型，提出高效率参量振荡系统的设计方法，为提升中红外激光技术水平和推进自主BGSe晶体应用提供研究基础。

4-14μm mid-infrared laser plays an important role in the military, environment, biology and scientific research, in order to meet the laser radar, optoelectronics confrontation, laser ablation and dynamics of biological macromolecules and other applications that require the development of a wide tuning high-energy mid-infrared OPO laser technology. But limited by the damage threshold and transmission range of the nonlinear crystal, and mid-infrared pump light source performance and parametric conversion efficiency and other issues, the current mid-infrared OPO energy is low, and the tuning range is limited. This project uses the homemade new laser crystal, develop high beam quality electro-optical Q-switched LD pumped 2.79μm erbium laser source, and design new mid-IR nonlinear crystals BaGa4Se7 (BGSe) based OPO to achieve wide 4-14μm mid-infrared tunable high-energy laser output. Focus on BGSe crystal wide tuning nonlinear characteristics, explore BGSe-OPO parametric oscillation mechanism, given the relationship between the phase mismatch, walk-off effect relationship, characteristics of the wavelength tuning and gain bandwidth changes and structural parameters and parameters of the pump cavity parameters. The establishment of high energy wide tuning gain theoretical model BGSe-OPO will be achieved, and proposed design methods of efficient OPO system, that will provide a foundation for research to enhance the level and mid-infrared laser technology and promote independent BGSe crystal applications.