宽温度范围微型化人眼安全激光器的研究

发布时间：2018-06-03 20:58

本文选题：Er3+/Yb3+共掺磷酸盐玻璃 + Co2+:MgAl2O4　；参考：《北京工业大学》2015年硕士论文

【摘要】：激光二极管(LD)泵浦的铒玻璃被动调Q全固态激光器可以产生1535nm附近的激光,同时其具有结构简单、体积小、便于携带等特点,在激光雷达、激光测距、目标指示、激光医疗和光纤通信中都有着广泛的应用需求。本论文设计了一款抗干扰能力强、结构紧凑、实际应用性价比非常高的微型化激光器。具体内容如下:1、通过对Er3+/Yb3+共掺磷酸盐玻璃三能级系统的速率方程进行分析,计算出泵浦光斑半径、最佳泵浦位置以及腔内往返损耗对激光影响。考虑在Er3+/Yb3+共掺磷酸盐玻璃晶体中,Yb3+主要起到敏化作用,Er3+掺杂浓度一定的情况下,Yb3+掺杂浓度决定着晶体对泵浦光的吸收效率。根据小信号增益公式,分析计算了增益介质对泵浦光吸收的最佳长度。2、分析1.5μm激光被动调Q晶体,根据Degnan被动调Q理论,计算不同初始透过率的调Q晶体所对应的输出镜最佳透过率,优化激光输出条件。3、激光器的总体结构设计,我们主要考虑两点:(1)结构紧凑稳定,一体化、微型化;(2)宽温度范围下激光器正常工作,散热性。激光器封装时,内部充入惰性气体,保证激光腔内元件不因温度、湿度变化出现结霜现象而损坏,增强了激光器工作的稳定性。解决了目前激光器在激光测距中存在的受温度、湿度影响比较大、激光器自身体积过大和不方便安装携带等问题。4、本文在理论分析基础上,以中心波长940nm二极管激光器作为泵浦源,选取Er3+/Yb3+共掺磷酸盐玻璃作为增益介质,Co2+:MgAl2O4作为被动调Q晶体,在泵浦能量9mJ,重复频率10 Hz,泵浦脉宽5ms的情况下,获得了脉冲能量130μJ,脉宽5ns,峰值功率20kW以上激光输出,光光转换效率1.5%。激光中心波长1535nm,线宽小于0.02nm,光束质量因子M2约1.3,激光输出的不稳定度小于5%。激光自由输出时,光光转换效率达到了17%。
[Abstract]:Laser diode (LD) pumped erbium glass passively switched Q all solid state laser can produce laser near 1535nm. At the same time, it has the characteristics of simple structure, small size, easy to carry and so on. It has wide application requirements in laser radar, laser range finding, target indication, laser medical treatment and optical fiber communication. This paper has designed an anti-jamming energy. Strong force, compact structure, practical application of very cost-effective micro laser. The specific contents are as follows: 1, through the analysis of the rate equation of the Er3+/Yb3+ Co doped phosphate glass three level system, the pump spot radius, the best pump position and the effect of the cavity return loss on the laser are calculated. The Co doped phosphate glass is considered in the case of Co doped phosphate glass. In the crystal of glass, Yb3+ mainly plays a sensitizing effect. Under the condition of certain Er3+ doping concentration, the doping concentration of Yb3+ determines the absorption efficiency of the crystal to pump light. According to the formula of small signal gain, the optimum length of the gain medium to the absorption of pump light is analyzed and calculated, and the 1.5 u m laser passive Q crystal is analyzed. According to the theory of Degnan passive Q, the calculation is calculated. The best transmittance of the output mirror of the Q crystal with different initial transmittance, the optimization of the laser output condition.3, the overall structure design of the laser, we mainly consider two points: (1) the structure is compact, stable, integrated, miniaturized, and (2) the laser is working normally and heat dissipation under the wide temperature range. The internal filling of the inert gas in the laser package ensures that the laser is filled with inert gases. The elements of the laser cavity are not damaged by the frosting phenomenon of the temperature and humidity, which enhances the stability of the laser work, and solves the problem that the laser is affected by the temperature, the humidity is larger, the volume of the laser is too large and the installation and carrying of the laser in the laser range finder, and the central wave is based on the theoretical analysis on the basis of the theoretical analysis. A long 940nm diode laser is used as the pump source, and Er3+/Yb3+ Co doped phosphate glass is selected as the gain medium. Co2+: MgAl2O4 is used as a passive Q crystal. In the case of pump energy 9mJ, repetition frequency 10 Hz and pump pulse width 5ms, the pulse energy is 130 micron, pulse width 5ns, peak power 20kW above laser output, optical conversion efficiency 1.5%. laser The center wavelength is 1535nm, the line width is less than 0.02nm, the beam quality factor M2 is about 1.3. The laser output instability is less than the free output of the 5%. laser, the optical conversion efficiency is 17%.
【学位授予单位】：北京工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN248

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