We demonstrate an efficient scheme to accelerate the self-similar pulse evolution and reduce the intensity noise of a free-running femtosecond fiber amplifier based on the pump wavelength optimization. Experiments and simulations indicate the enhanced tolerances of the pulse self-similar amplification to the seed signal power and pump wavelength fluctuations, with the optimum 915 nm pump wavelength. ∼20% increase in the compressed pulse quality and ∼31% reduction in the amplifier root-mean-square (RMS) relative intensity noise (RIN) (1.5 kHz to 5 MHz) have been observed, even with a more than 4 times higher pump laser diode (LD) RIN than the case of 976 nm. ∼50 fs transform-limited pulses are generated with the ∼0.03% amplifier RMS RIN. The proposed scheme can lower the requirements of low-noise self-similar femtosecond fiber amplifiers on the power stability of the seed oscillator and the thermal control of the pump LD, thus denoting potentials for the various satellite-based high-precision applications of femtosecond laser in space.

中文翻译：

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通过泵浦波长优化提高飞秒光纤放大器的性能

我们展示了一种有效的方案，可基于泵浦波长优化，加速自相似脉冲的演化并降低自由运行的飞秒光纤放大器的强度噪声。实验和仿真表明，在最佳915 nm泵浦波长下，脉冲自相似放大对种子信号功率和泵浦波长波动的容限有所提高。观察到压缩脉冲质量提高了20％，放大器的均方根（RMS）相对强度噪声（RIN）（1.5 kHz至5 MHz）降低了31％，即使高出4倍以上泵浦激光二极管（LD）RIN比976 nm的情况下。约0.03％的放大器RMS RIN产生约50 fs的变换限制脉冲。