Su Meng, Meng Xianghao, Zhao Xianglong, Gong Zhaoqing, Mao Dun, Guo Xiaoyang, Tai Boyin, Huang Yutao, Zhang Guoxin, Li Pingxue
Opt Express. 2025 Feb 24;33(4):7218-7228. doi: 10.1364/OE.554169.
A hybrid chirped pulse amplification (CPA) system is demonstrated based on a fiber seed source and a three-stage Yb:YAG crystal amplifier. We investigate the mechanism of gain narrowing in a CPA system through theoretical and experimental research. The gain narrowing can be suppressed by pre-shaping the pulse spectrum via a fiber Bragg grating (FBG) with a specifically designed spectral characteristic before amplification. The compact compressor is based on a transmission diffraction grating with a line density of 1739 lines/mm. The high-order dispersion within the CPA system is compensated by a tunable dispersion stretcher. At a repetition rate of 200 kHz, the compressed average power of 64.15 W and pulse duration of 431 fs, corresponding to a pulse energy of 321 μJ and a peak power of 744 MW, is obtained. The polarization extinction ratio of the pulses is about 23 dB, and the M factor is less than 1.16. In addition, the long-term power stability is tested, and the root mean square of the average power is below 0.17% over 39.5 hours. Such good performance is beneficial to ultrafast material processing in scientific research and industrial fields.
基于光纤种子源和三级Yb:YAG晶体放大器演示了一种混合啁啾脉冲放大（CPA）系统。我们通过理论和实验研究探讨了CPA系统中增益窄化的机制。在放大之前，可通过具有特定设计光谱特性的光纤布拉格光栅（FBG）对脉冲光谱进行预整形来抑制增益窄化。紧凑的压缩器基于线密度为1739线/毫米的透射衍射光栅。CPA系统内的高阶色散由可调谐色散展宽器补偿。在200 kHz的重复频率下，获得了64.15 W的压缩平均功率和431 fs的脉冲持续时间，对应于321 μJ的脉冲能量和744 MW的峰值功率。脉冲的偏振消光比约为23 dB，M因子小于1.16。此外，测试了长期功率稳定性，在39.5小时内平均功率的均方根低于0.17%。如此良好的性能有利于科研和工业领域的超快材料加工。
