We report, to the best of our knowledge, the first mode-locked operation of Yb:YLF gain media at cryogenic temperatures. A saturable Bragg reflector was used for initiating and sustaining mode locking. Once aligned, the system was self-starting and quite robust. Using output couplers in the 10–40% range, 3–5 ps long pulses with an average power as high as 28 W were achieved. The repetition rate was 46.45 MHz, and the corresponding pulse energy and peak power were as high as 602 nJ and 126.5 kW, respectively. The central wavelength of the mode-locked pulses could be tuned in the 1013.5–1019 nm range using an intracavity birefringent filter. The achieved output power performance is two to three orders of magnitude higher than previous room-temperature Yb:YLF systems.

中文翻译：

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高功率被动锁模低温 Yb:YLF 激光器

据我们所知，我们报告了 Yb:YLF 增益介质在低温下的第一次锁模操作。饱和布拉格反射器用于启动和维持锁模。一旦对齐，系统就会自动启动并且非常强大。使用 10-40% 范围内的输出耦合器，实现了 3-5 ps 长脉冲，平均功率高达 28 W。重复频率为46.45 MHz，相应的脉冲能量和峰值功率分别高达602 nJ和126.5 kW。锁模脉冲的中心波长可以使用腔内双折射滤波器在 1013.5-1019 nm 范围内进行调谐。实现的输出功率性能比以前的室温 Yb:YLF 系统高两到三个数量级。