3~5 μm中红外辐射位于大气传输窗口, 具有广泛的应用前景。目前, 固体激光器获得3~5 μm中红外辐射的途径主要是基于光参量振荡(OPO)的方法。与之相比, 以直接抽运为代表的新型中红外固体激光器在总体设计原理和激光器结构上都更为简单。目前, 随着相关晶体材料和对应抽运源的逐步成熟, 直接抽运中红外激光器迅速发展。总结了以Fe∶ZnSe、Ho∶BYF和Dy∶PGS三种晶体材料为代表的直接抽运中红外固体激光器, 详细介绍了其关键技术和国内外主要研究进展, 分析了其发展的重点和难点。

Mid-infrared (3-5 μm) is in the range of atmospheric transmission window, which has broad application prospects. So far, the main way to obtain the mid-infrared radiation by solid-state lasers is based on the optical parameter oscillator (OPO) technology. The design principle and structures of new type mid-infrared lasers, especially directly pumping of mid-infrared lasers are not so complicated compared with OPO. With the development of crystal material and relevant pump sources, the directly pumping of mid-infrared lasers develops rapidly. Directly pumping of mid-infrared lasers, their key techniques and recent research advances, represented by Fe∶ZnSe laser, Ho∶BYF laser and Dy∶PGS laser, are summarized. The key and difficult points are analyzed at last.