28 μm passively Q-switched Er:CaF_2 diode-pumped laser

作者：Chun Li, Jie Liu, Shouzhen Jiang, Shicai Xu, Weiwei Ma, Jingya Wang, Xiaodong Xu, Liangbi Su · 发表于：Optical Materials Express · 年份：2016 · DOI：10.1364/ome.6.001570 · 被引用次数：67 · 研究领域：Advanced Fiber Laser Technologies、Solid State Laser Technologies、Photorefractive and Nonlinear Optics

A mid-infrared Er doped CaF2 crystal was successfully grown by the bridgeman method. Efficiently continuous wave and Q-switched laser operations were demonstrated at 2.8 μm with a 4 at.% Er doped CaF2 crystal end-pumped by a fiber-coupled 974 nm diode laser. The continuous wave output power of 295 mW was obtained in a compact linear cavity. A stable 2.8 μm passively Q-switched Er:CaF2 laser was also demonstrated with a graphene saturable absorber. Under an absorbed pump power of 2.353 W, an average output power of 172 mW was generated with a pulse duration of 1.324 μs and a repetition rate of 62.70 kHz, corresponding to the single pulse energy of 2.74 μJ and the peak power of 2.07 W, respectively. The high-quality Er:CaF2 crystal and the monolayer graphene are an ideal combination to directly obtain a near 3 μm mid-infrared region pulse laser.