脉冲LD间歇抽运Tm:YAG 2μm声光调Q激光器

发布时间：2019-03-28 08:11

【摘要】：激光二极管(LD)抽运的铥掺杂(Tm~(3+))固体激光器(DPSSL)是获得2μm波段的激光的重要途径,其在众多领域均已显示出不可或缺的应用需求。本论文从理论和实验两个方面对脉冲LD间歇抽运Tm:YAG 2μm声光调Q激光器进行了研究。主要研究内容为:理论上,基于Tm~(3+)能级跃迁情况,对脉冲抽运单掺Tm~(3+)调Q激光器速率方程进行建立与求解,从理论上计算激光器输出特性;使用Comsol软件对Tm:YAG晶体内部热场分布进行模拟;利用积分变换求解瞬态热传导方程,并利用Matlab软件模拟Tm:YAG晶体热透镜焦距;在考虑热焦距情况下设计两种间歇抽运谐振腔,为实验的开展提供理论依据。实验上,首先开展了脉冲LD抽运Tm:YAG热焦距测量实验,单端抽运100Hz注入能量14.5-130.2mJ,热焦距由768mm降至269mm;200Hz注入能量14.5-160mJ,热焦距由968mm降至124mm。双端抽运100Hz注入能量14.5-130.2mJ,热焦距由535mm降至126mm;200Hz注入能量14.5-160mJ,热焦距由450mm降至75mm。其次开展脉冲LD间歇抽运单块双端键合Tm:YAG声光调Q激光器实验研究。调Q 200Hz时,泵浦118mJ,输出5.41mJ,斜率效率12.79%,脉宽395.4ns,波长2013.94nm,光束质量在x方向1.49,y方向1.59;再次开展脉冲LD间歇抽运单端键合Tm:YAG双棒串接声光调Q激光器实验。单块晶体重频100Hz,调Q 200Hz时,泵浦176mJ,输出6.04mJ,斜率效率13.06%,脉宽377.9ns,波长2014.22nm,光束质量在x方向1.29,在y方向1.45。结果证明间歇抽运技术有提高输出能量并使重频成倍增长的作用。最后,改变重频条件、泵浦方式进行对比试验。结果表明,间歇抽运下的激光器运转重频是与激光工作物质的上能级寿命密切相关的。
[Abstract]:Laser diode (LD) pumped thulium doped (Tm~ (3) solid-state laser (DPSSL) is an important way to obtain 2 渭 m-band laser. It has shown an indispensable application demand in many fields. In this paper, a pulsed LD intermittently pumped Tm:YAG 2 渭 m acousto-optic Q-switched laser is studied theoretically and experimentally. The main research contents are as follows: theoretically, based on the transition of Tm~ (3) level, the rate equation of pulse pumped single-doped Tm~ (3) Q-switched laser is established and solved, and the output characteristics of the laser are calculated theoretically. The thermal field distribution in Tm:YAG crystal is simulated by Comsol software, the transient heat conduction equation is solved by integral transformation, and the focal length of Tm:YAG crystal thermal lens is simulated by Matlab software. Considering the thermal focal length, two kinds of intermittently pumped resonators are designed, which provide the theoretical basis for the development of the experiment. In the experiment, the measurement experiment of thermal focal length of pulsed LD pumped Tm:YAG was carried out. The single-end pumped 100Hz injection energy was 14.5 渭 130.2mJ, the thermal focal length was decreased from 768mm to 269mm and 200Hz injection energy 14.5x160mJ, and the thermal focal length was decreased from 968mm to 124mm. the thermal focal length was reduced from 968mm to 124mm. The injection energy of two-end pumped 100Hz is 14.5 脳 130.2mJ, the thermal focal length is reduced from 535mm to 126mm / 200Hz injection energy 14.5x160mJ, and the thermal focal length is reduced from 450mm to 75mm. Secondly, an experimental study of pulsed LD intermittently pumped acousto-optic Q-switched Tm:YAG laser with single-block and two-end bonding is carried out. When Q-switched 200Hz is used, the pump is 118mJ, the output is 5.41mJ, the slope efficiency is 12.79%, the pulse width is 395.4 ns, the wavelength is 2013.94 nm, the beam quality is 1.49 in x direction and 1.59 in y direction. The experiment of pulsed LD intermittent pumping single-end bonded Tm:YAG double rod series-connected acousto-optic Q-switched laser is carried out again. Single crystal repetition frequency 100Hz, Q-switched 200Hz pumped 176 MJ, output 6.04 MJ, slope efficiency 13.06%, pulse width 377.9 ns, wavelength 2014.22 nm, beam quality in x direction 1.29, y direction 1.45. The results show that the intermittent pumping technique can increase the output energy and double the repetition frequency. Finally, the pump mode is compared by changing the condition of repetition frequency. The results show that the re-operation frequency of the laser under intermittent pumping is closely related to the upper-level lifetime of the laser material.
【学位授予单位】：长春理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN248

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