Herein, we report a homemade new Nd:YAG crystal rod that contains a gradient dopant of 0.39–0.80 at.% ${\mathrm{Nd}}^{3+}$ from end to end, achieving superior performance of a 2 kHz Nd:YAG pulse laser at 1064 nm. The optical-to-optical conversion efficiency reached 53.8%, and the maximum output power of the laser was 24.2 W, enhanced by 35.9% compared with a uniform crystal rod with the same total concentration of ${\mathrm{Nd}}^{3+}$. Significantly, our experiments revealed that the gradient concentration crystal produced a relatively even pumping distribution along the rod axis, greatly reducing the temperature gradient as well as having a smaller thermal effect. The pump and thermal distribution smoothing obviously improved the features of laser oscillation and output.

中文翻译：

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基于梯度掺杂晶体的 2 kHz 脉冲 Nd:YAG 激光器的卓越性能

在此，我们报告了一种自制的新型 Nd:YAG 晶体棒，其中包含 0.39–0.80 at.% 的梯度掺杂剂 ${钕}^{3+}$从头到尾，在 1064 nm 处实现 2 kHz Nd:YAG 脉冲激光器的卓越性能。光光转换效率达到53.8%，激光器的最大输出功率为24.2 W，比相同总浓度的均匀晶棒提高了35.9%。${钕}^{3+}$. 值得注意的是，我们的实验表明，梯度浓度晶体沿杆轴产生了相对均匀的泵送分布，大大降低了温度梯度，同时具有更小的热效应。泵浦和热分布平滑明显改善了激光振荡和输出的特性。