处于3~5 μm波段的激光源在遥感、环境保护、医疗、通信和红外对抗等民用和军用领域都有广阔的应用前景。Fe2+:ZnSe晶体由于在材料特性和光学特性等方面都具有明显优势,是3~5 μm波段极具潜力的激光介质之一。在室温条件下利用自制非链式脉冲HF激光器作为泵浦光源, 对晶体直径为10 mm, 厚度1 mm, Fe2+离子掺杂浓度为3×1019/cm3的Fe2+:ZnSe晶体进行了研究, 获得了中心波长4 295 nm、最大输出能量78.8 mJ的中红外激光输出。输出激光能量相对于晶体吸收泵浦能量的转换效率为27.7%, 斜率效率达28.8%。采用小角度(3°)斜入射的方案很好地解决了Fe2+:ZnSe激光器谐振腔镜镀膜问题。

Lasers in the 3-5 μm waveband have many important scientific and military applications such as remote sensing, environmental protection, medical treatment, communication and infrared countermeasures. Fe2+:ZnSe crystal has become one of the most promising materials to generate laser in this region due to its advantages in material and optical properties. The characteristics of a polycrystalline ZnSe sample, which diffusion-doped with Fe2+ ions at a concentration of 3×1019/cm3, were investigated. The diameter and the thickness of the sample were 10 mm and 1 mm, respectively. The output characteristics of the Fe2+:ZnSe laser, which was excited by a non-chain electric-discharge pulsed HF laser, were studied at room temperature. A mid-infrared laser with the maximum output energy of 78.8 mJ at a center wavelength of 4 295 nm was obtained. The efficiency respecting to the absorbed pump energy was 27.7% and the slope efficiency was as high as 28.8%. The Fe2+:ZnSe laser was pumped at a small angle(3°) with respect to the optical axis of the laser cavity instead of orthogonal-pump. It solved the problems that a HF laser and a Fe2+:ZnSe laser are both in the mid-infrared band.