蓝光泵浦Pr:YLF直接获得可见光的全固态激光器研究

发布时间：2018-05-13 18:15

本文选题：Pr~(3+):YLF + 激光器　；参考：《长春理工大学》2017年硕士论文

【摘要】：橙红(600nm-660nm)波段的激光在激光投影、激光彩色显示、平版印刷及激光通信等领域都具有广泛的应用。近年来利用非线性频率变换的方法输出该波段激光是相对稳定且比较成熟的方法。但是这种方法必须进行至少一次以上的非线性频率变换过程,导致光-光转换效率低,相比于直接获得的方式,其劣势显然可见。随着市场对连续橙光光源的需求不断增加,人们开始寻找能直接输出橙红光波段激光的新型晶体。蓝光泵浦Pr~(3+)激光器可以直接产生绿光、橙光和红光,这是相对有效且简便的方法。因此本论文对蓝光LD泵浦Pr~(3+):YLF激光器直接产生可见光展开了以下研究。1.测量了不同偏振方向的Pr~(3+):YLF晶体的激光特性,获得了相关晶体参数,进而通过推导四能级速率方程理论建立了Pr~(3+)激光器的数学模型,并模拟了激光器输出镜透过率和光斑半径对激光输出特性的影响,在此基础上对输出镜透过率进行了优化设计。2.研究了在激光谐振腔内插入法布里-珀罗(F-P)标准具来选择Pr~(3+)激光波长的相关理论。通过调节标准具在激光谐振腔里的厚度和倾斜角度来控制不同波长间的损耗,从而实现相邻波长的选择。并模拟了标准具的厚度和倾斜角度对激光阈值的影响,确定出可以实现Pr~(3+)激光多波长输出的标准具的最优厚度和角度,为实验奠定了理论基础;3.最后根据前面对Pr~(3+):YLF激光器的理论模拟以及在谐振腔内插入F-P标准具的优化设计,开展了蓝光抽运Pr~(3+):YLF晶体产生可见光的实验研究:(1)对8WLD泵浦光束进行了整形,并测试了2W8WLD蓝光抽运源的输出特性,计算出a切c切晶体的泵浦功率吸收效率;(2)通过比较不同偏振方向的晶体、不同曲率半径和透过率的输出镜,获得a切晶体639nm红光最高输出功率为492mW、c切晶体607nm橙光最高输出功率为177mW,并且尝试了采用三镜V型腔结构,进行了双端泵浦抽运Pr~(3+):YLF晶体输出橙光的实验,获得了最高输出功率为58mW的607nm橙光;(3)通过调节标准具的角度,成功获得了最高功率为30mW的607nm639nm双波长、25mW的604nm607nm639nm三波长激光输出,实验结果验证了理论模拟的正确性。
[Abstract]:The laser in the range of 600nm-660nm) has been widely used in the fields of laser projection, laser color display, lithography and laser communication. In recent years, it is a relatively stable and mature method to output the laser band by nonlinear frequency conversion. However, this method has to undergo at least one nonlinear frequency conversion process, which leads to the low efficiency of optical-optical conversion, and its disadvantage is obvious compared with the method of direct acquisition. With the increasing market demand for continuous orange light sources, people begin to look for new crystals that can directly output orange red band lasers. Blue pumped Pr~(3) laser can produce green, orange and red light directly, which is a relatively effective and simple method. Therefore, in this thesis, the following research has been done on the direct generation of visible light from Pr~(3: YLF laser pumped by blue LD. The laser characteristics of Pr~(3: YLF crystal with different polarization directions are measured, and the related crystal parameters are obtained. The mathematical model of Pr~(3) laser is established by deducing the four-level rate equation theory. The effects of the transmittance of the laser output mirror and the radius of the spot on the laser output characteristics are simulated. On the basis of this, the transmittance of the output mirror is optimized. The theory of choosing Pr~(3) laser wavelength by inserting Fabry-Perot F-P standard device into laser resonator is studied. The loss between different wavelengths is controlled by adjusting the thickness and tilt angle of the standard device in the laser resonator, and the selection of adjacent wavelengths is realized. The influence of the thickness and tilt angle of the standard device on the laser threshold is simulated, and the optimum thickness and angle of the standard device which can realize the multi-wavelength output of Pr~(3 are determined, which lays a theoretical foundation for the experiment. Finally, based on the theoretical simulation of the Pr~(3: YLF laser and the optimized design of the F-P standard device inserted into the resonator, an experimental study on the visible light produced by the blue-pumped Pr~(3: YLF crystal is carried out. The output characteristics of 2W8WLD blue light pump source are tested. The pump power absorption efficiency of a cut c cut crystal is calculated by comparing the crystal with different polarization direction, the output mirror with different curvature radius and transmittance. The maximum output power of a cut crystal 639nm red light is 492 MW / c. The maximum output power of 607nm orange light is 177mW, and a three-mirror V-cavity structure is used to pump the orange light from Pr~(3: YLF crystal. By adjusting the angle of the standard device, the maximum output power of 607nm orange laser with the highest output power of 58mW is obtained, and the 607nm639nm double wavelength 25MW 604nm607nm639nm three-wavelength laser output with the highest power of 30mW is obtained. The experimental results verify the correctness of the theoretical simulation.
【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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