新型铥掺杂氧化镥钪陶瓷光谱展宽效应及2μm波段超快激光特性研究

2μm波段超快激光是近年来全固态超快激光技术的研究热点之一。新型铥掺杂氧化镥钪陶瓷同时具备高的热导率和独特的光谱特性，是获得高平均功率2μm超快激光的有潜力的激光介质。本项目将系统研究该新型陶瓷的光谱展宽效应，评价其在2μm波段高平均功率超快激光的运转特性，具体内容包括：明确铥离子掺杂浓度、镥钪比对陶瓷热导率的影响规律；揭示荧光增益线宽、受激发射截面、激光上能级寿命等随镥钪比的变化趋势，找到平衡该型激光陶瓷热导率与光谱展宽效应的关键参数；探究激光陶瓷特性、饱和吸收体参数与超快激光输出功率、脉冲宽度等的内在关系，基于SESAM、石墨烯等成熟的锁模元件，实现LD泵浦陶瓷激光器连续波锁模运转, 获得平均输出功率>1W的2μm波段飞秒激光输出。希望通过本项目的实施，能够为高平均功率2μm波段超快激光产生提供有效的材料和技术支撑。

Laser sources delivering ultrashort pulses in the 2 μm spectral region are becoming a research focus in the field of ultrafast all-solid-state laser technology. Due to the advantage of high thermal conductivity and distinctive spectroscopic characteristics, novel Tm:(LuxSc1-x)2O3 ceramic is a promising laser material for achieving high power ultrafast lasers in the 2 μm spectral region. This project will systematically study the spectral lines broadening effect of the novel ceramic and evaluate the performance of high power ultrafast Tm:(LuxSc1-x)2O3 ceramic laser in the 2 μm spectral region. The main research contents include: understanding the influence of Tm3+ doping concentration and ratio of Sc/Lu on the thermal conductivity of ceramic; indicating the dependence of the emission linewidth, stimulated emission cross-section and lifetime of upper laser level on the ratio of Sc/Lu, and finding the key parameters for balancing the thermal conductivity and spectral lines broadening in Tm:(LuxSc1-x)2O3 ceramic; exploring the influence of the characteristics of laser ceramic and saturable absorber on the average output power and pulse width, realizing the mode-locking operation of LD pumped Tm:(LuxSc1-x)2O3 ceramic laser by use of SESAM or graphene, and generating the femtosecond laser pulses in the 2 μm spectral region with average output power exceeding 1W. It is hoped that the efficient laser materials and technique for supporting high average power ultrashort pulses generation in the 2 μm spectral region can be obtained by the implementation of this project.