Yuan Junjie, Yang Houwen, Cheng Wenyong
Appl Opt. 2025 Feb 20;64(6):1454-1458. doi: 10.1364/AO.549727.
In this study, we successfully developed a high beam quality Q-switched pulsed laser operating at a wavelength of 1064 nm, featuring a repetition frequency of 25 kHz and an power output of 150.2 W. The system comprises a seed laser oscillator coupled with a four-stage traveling-wave amplifier, utilizing : crystals as the medium for both oscillation and amplification stages. To mitigate the thermal effects on the crystal, we meticulously selected an appropriate laser diode (LD) wavelength, optimized the concentration and length of the crystals, and applied indium welding techniques. Additionally, we implemented thermal spherical aberration compensation to further enhance the beam quality and overall output power. We conducted an extensive analysis on the beam quality and amplification efficiency across each stage of the system. Ultimately, we achieved a frequency doubling power of 49 W using a type-I non-critical phase matching crystal, resulting in a conversion efficiency of 32.6%. Our findings illustrate the viability of employing : crystals in multi-stage amplification setups to produce high-power lasers with pulse durations on the order of hundreds of nanoseconds.
在本研究中，我们成功研制出一种高光束质量的调Q脉冲激光器，其工作波长为1064 nm，重复频率为25 kHz，输出功率为150.2 W。该系统包括一个种子激光振荡器和一个四级行波放大器，在振荡和放大阶段均使用:晶体作为介质。为减轻晶体上的热效应，我们精心选择了合适的激光二极管(LD)波长，优化了晶体的浓度和长度，并应用了铟焊接技术。此外，我们实施了热球差补偿以进一步提高光束质量和整体输出功率。我们对系统各阶段的光束质量和放大效率进行了广泛分析。最终，我们使用I型非临界相位匹配晶体实现了49 W的倍频功率，转换效率为32.6%。我们的研究结果表明，在多级放大装置中使用:晶体来产生脉冲持续时间在数百纳秒量级的高功率激光器是可行的。
