In this study, a high-energy, temporally shaped picosecond ultraviolet (UV) laser running at 100 Hz is demonstrated, with its pulses boosted to 120 mJ by cascaded regenerative and double-pass amplifiers, resulting in a gain of more than 108. With precise manipulation and optimization, the amplified laser pulses were flat-top in the temporal and spatial domains to maintain high filling factors, which significantly improved the conversion efficiency of the subsequent third harmonic generation (THG). Finally, 91 mJ, 470 ps pulses were obtained at 355 nm, corresponding to a conversion efficiency as high as 76%, which, as far as we are aware of, is the highest THG efficiency for a high-repetition-rate picosecond laser. In addition, the energy stability of the UV laser is better than 1.07% (root mean square), which makes this laser an attractive source for a variety of fields including laser conditioning and micro-fabrication.

中文翻译：

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来自效率增强、三倍频激光器的高能量、高重复率紫外脉冲

在这项研究中，展示了一种运行频率为 100 Hz 的高能、时间形状的皮秒紫外 (UV) 激光器，其脉冲通过级联再生和双通放大器提高到 120 mJ，增益超过 108. 通过精确的操控和优化，放大后的激光脉冲在时域和空间域中都是平顶的，以保持较高的填充因子，从而显着提高了后续三次谐波产生（THG）的转换效率。最后，在 355 nm 处获得了 91 mJ、470 ps 的脉冲，对应的转换效率高达 76%，据我们所知，这是高重复率皮秒激光器的最高 THG 效率。此外，紫外激光器的能量稳定性优于 1.07%（均方根），这使得该激光器成为包括激光调节和微加工在内的各种领域的有吸引力的光源。