A thin-disk multi-pass pump scheme with large laser aperture
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摘要: 提出了一种基于4-f成像的新型碟片多程泵浦方案。该方案由一片大抛物镜和两组转折棱镜组成多程泵浦的基本传输结构。这种方案拥有0~90°的理论通光孔径角,比目前常见的泵浦结构方案的通光孔径角范围都更宽。在该方案中,碟片上的泵浦光斑具有良好的重合性和锐利的边缘。该泵浦结构在注入344 W、18次泵浦的条件下实现了141 W的多模激光输出,光-光转换效率达到41%,斜率效率接近50%。Abstract: In this paper, a novel multi-pass pump scheme based on 4-f imaging is proposed. The scheme consists of a large parabolic mirror and two groups of folding prisms, which are the basic propagation structure of the scheme. The pump scheme has a theoretical aperture of 0−90° for laser transmission, which is wider than that of the commonly used pump schemes. The pump spot on the disk in the pump scheme has a good coincidence with sharp edges. With 344 W power injection and 18 times pumping, an average output of 141 W multi-mode laser is achieved. The optical to optical efficiency reaches 41%, and the slope efficiency is close to 50%.
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Key words:
- thin-disk laser /
- multi-pass pump /
- 4-f imaging system /
- spot uniformity /
- parabolic mirror
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图 2 三角形的泵浦光斑经过碟片(a)1次(b)12次之后所形成的光斑形状[11]
Figure 2. Appearance of the spot of propagating (a) once (b) 12 times through the thin-disk for a triangle shaped pump spot
表 1 3种泵浦方案的对比
Table 1. Comparison of the three pump schemes
evaluating indicator ADSP RDDP RDSP sharpness of pump spot radially diffusion diffusion in x and y direction diffusion in x and y direction pump spot shape that coincides perfectly circle or regular polygon
with appropriate anglesymmetric about x axis and y axis symmetric about x axis and y axis laser transmission angle small angle only small angle blocked 0°~90° in theory anti-disturbance ability[8] low high low number of reflections on
mirrors in a cycle4 5 4 cost low (one parabolic mirror) high (two parabolic mirrors) low (one parabolic mirror) adjusting difficulty high low medium -
[1] Giesen A, Speiser J. Fifteen years of work on thin-disk lasers: results and scaling laws[J]. IEEE Journal of Selected Topics in Quantum Electronics, 2007, 13(3): 598-609. doi: 10.1109/JSTQE.2007.897180 [2] 崔文达, 韩凯, 王红岩, 等. 半导体泵浦盘片激光器的技术发展[J]. 激光与红外, 2016, 46(4):387-393. (Cui Wenda, Han Kai, Wang Hongyan, et al. Recent advances of diode-pumped thin disk laser[J]. Laser & Infrared, 2016, 46(4): 387-393 doi: 10.3969/j.issn.1001-5078.2016.04.002 [3] Erhard S, Giesen A, Karszewski M, et al. Novel pump design of Yb: YAG thin disc laser for operation at room temperature with improved efficiency[C]//Proceedings of the Advanced Solid State Lasers. 1999. [4] Killi A, Zawischa I, Sutter D, et al. Current status and development trends of disk laser technology[C]//Proceedings of the SPIE 6871 Solid State Lasers XVII: Technology and Devices. 2008: 68710L. [5] Gottwald T, Stolzenburg C, Bauer D, et al. Recent disk laser development at Trumpf[C]//Proceedings of the SPIE 8547 High-Power Lasers 2012: Technology and Systems. 2012: 85470C. [6] Sven-Silvius S, Tina G, Vincent K, et al. Recent development of disk lasers at TRUMPF[C]//Proceedings of the SPIE 9726 Solid State Lasers XXV: Technology and Devices. 2016: 972615. [7] Schuhmann K, Hänsch T W, Kirch K, et al. Thin-disk laser pump schemes for large number of passes and moderate pump source quality[J]. Applied Optics, 2015, 54(32): 9400-9408. doi: 10.1364/AO.54.009400 [8] Huang Yan, Zhu Xiao, Zhu Guangzhi, et al. A multi-pass pumping scheme for thin disk lasers with good anti-disturbance ability[J]. Optics Express, 2015, 23(4): 4605-4613. doi: 10.1364/OE.23.004605 [9] Song Enmao, Zhu Guangzhi, Wang Hailin, et al. Minimizing thermal load and stabilizing mode in Yb: YAG thin disk laser by 1030 nm multi-pass pumping[J]. IEEE Photonics Technology Letters, 2020, 32(16): 1011-1014. doi: 10.1109/LPT.2020.3008410 [10] Chen Hantian, Song Enmao, Dong Jing, et al. Compact thin-disk multipass amplifier tolerant of strong disk thermal distortions[C]//Proceedings of CLEO: Science and Innovations 2020. 2020. [11] 黄彦. 碟片激光器泵浦均匀性的研究[D]. 武汉: 华中科技大学, 2016: 90-93Huang Yan. The study of pumping uniformity in thin disk lasers[D]. Wuhan: Huazhong University of Science and Technology, 2016: 90-93