Kerr-lens mode-locked polycrystalline Cr:ZnS femtosecond laser pumped by a monolithic Er:YAG laser

We demonstrated a Kerr-lens mode-locked polycrystalline Cr：ZnS laser pumped by a narrow-linewidth linearpolarised monolithic Er：YAG nonplanar ring oscillator operated at 1645 nm. With a 5-mm-thick sapphire plate for intracavity dispersion compensation, a compact and stable Kerr-lens mode-locking operation was realised. The oscillator delivered 125-fs pulses at 2347 nm with an average power of 80 m W. Owing to the special polycrystalline structure of the Cr：ZnS crystal, the second to fourth harmonic generation was observed by random quasi-phase-matching.

65mJ室温Fe^2＋∶ZnSe中红外激光器

Fe^(2+):ZnSe晶体作为3~5μm波段极具潜力的中红外激光介质之一,在材料特性和转换效率等方面具有明显优势。对Fe^(2+):ZnSe晶体的吸收特性进行了研究,利用自制放电引发的非链式脉冲HF激光抽运Fe^(2+)掺杂浓度为4×1018 cm^(-3)、尺寸为10mm×10mm×5mm的Fe^(2+):ZnSe晶体,在室温下获得了65mJ的高能量Fe^(2+):ZnSe中红外激光输出,光光转换效率为31%,输出激光能量相对于晶体吸收抽运光能量的斜率效率可达37%。