1 上海大学理学院, 上海 200444
2 中国科学院上海光学精密机械研究所高功率光纤激光技术实验室, 上海 201800
3 中国科学院上海光学精密机械研究所上海市全固态激光器与应用技术重点实验室, 上海 201800
4 中国科学院上海光学精密机械研究所强激光材料重点实验室, 上海 201800
不同切割方向的Ho∶YAP晶体的激光输出特性存在差别。针对掺杂浓度为0.5%(原子数分数)的Ho∶YAP晶体开展a、b、c三种切割方向的激光输出特性实验研究。采用最大输出功率为44.3 W的1915 nm掺铥光纤激光器端面泵浦Ho∶YAP晶体,在三种切割方向上均获得了大于20 W的连续激光输出,其中b向切割晶体输出激光的中心波长近2118 nm,最大功率为23.6 W,斜率效率为61.98%,a向切割晶体与b向切割晶体的输出结果相近,c向切割晶体在达到最大输出功率时的中心波长为2129 nm;当采用腔内声光调Q获得脉冲输出时,a、c向切割晶体出现了中心波长偏移和多波长起振现象,而b向切割晶体则获得了中心波长近2118 nm的稳定脉冲输出,且其在重复频率为20 kHz时的最大平均输出功率为22.3 W,脉宽为20 ns,斜率效率为55.22%,光束质量因子分别为 Mx2=1.81和 My2=1.50。选用b向切割的Ho∶YAP晶体更有利于实现稳定且高效的2118 nm连续激光及纳秒级脉冲激光输出。
材料 Ho∶YAP晶体 输出特性 切割方向 2 μm激光
Author Affiliations
Abstract
1 Key Laboratory of Space Laser Communication and Detection Technology, Chinese Academy of Sciences, Shanghai 201800, China
2 Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
3 Shanghai Key Laboratory of All Solid-State Laser and Applied Techniques, Shanghai 201800, China
4 Key Laboratory of Materials for High Power Laser, Chinese Academy of Sciences, Shanghai 201800, China
A 1.5 J Nd:LuAG ceramic active mirror laser amplifier with a high beam quality is demonstrated in which a 0.8% (atomic fraction) Nd-doped Nd:LuAG ceramic disk with a diameter of 64 mm and a thickness of 5.5 mm is used as a laser gain medium. A maximum single-pass small-signal gain of 2.59 is measured when the pump energy is 11.5 J, with an injected seed energy of 0.4 J; a maximum output energy of 1.5 J is obtained at the repetition rate of 10 Hz. A far-field beam spot 1.25 times the diffraction limit (DL) is achieved by using a stimulated Brillouin scattering phase conjugation mirror (SBS-PCM) for wavefront correction.
high energy lasers disk laser amplifiers Nd:LuAG ceramic high beam quality Chinese Optics Letters
2020, 18(2): 021401
