Wang Wenlong, Lin Wei, Cheng Huihui, Zhou Yi, Qiao Tian, Liu Yicai, Ma Pengfei, Zhou Shifeng, Yang Zhongmin
Opt Express. 2019 Apr 15;27(8):10438-10448. doi: 10.1364/OE.27.010438.
Fundamental repetition rates of 3.1 GHz, 7.0 GHz, and 12.5 GHz in passively modelocked Yb-doped fiber lasers are demonstrated. To the best of our knowledge, the fundamental repetition rate of 12.5 GHz is the highest value for 1.0 μm mode-locked fiber lasers. The mode-locked oscillator has a peak wavelength of 1047.5 nm and a pulse duration of 1.9 ps. The repetition rate signal has a signal-to-noise ratio of 57 dB. The peak wavelength of mode-locked spectra gradually makes a blue-shift and the modelocked threshold power increases with an increase in pulse repetition rate. Furthermore, in contrast to most of the all-normal-dispersion mode-locked fiber lasers, the present linear resonator (e.g., length < 1 cm) allows the buildup of gain-guided soliton without any filter effect. To unveil the underlying pulse shaping mechanism, a combined model comprising dynamic rate equations and the generalized nonlinear Schrödinger equation is established. Surprisingly, an essential gain filtering effect, which is contributed by a 26-nm gain bandwidth, is revealed and can verify the gain-guided pulse dynamics. Moreover, the pulse build-up in temporal and frequency domain, like spectral evolution and gain bandwidths, is numerically carried out in detail.
展示了被动锁模掺镱光纤激光器中3.1 GHz、7.0 GHz和12.5 GHz的基频重复率。据我们所知，12.5 GHz的基频重复率是1.0μm锁模光纤激光器的最高值。锁模振荡器的峰值波长为1047.5 nm，脉冲持续时间为1.9 ps。重复率信号的信噪比为57 dB。锁模光谱的峰值波长逐渐发生蓝移，锁模阈值功率随脉冲重复率的增加而增大。此外，与大多数全正色散锁模光纤激光器不同，目前的线性谐振器（例如，长度<1 cm）无需任何滤波效应就能实现增益引导孤子的积累。为了揭示潜在的脉冲整形机制，建立了一个包含动态速率方程和广义非线性薛定谔方程的组合模型。令人惊讶的是，揭示了一种由26 nm增益带宽产生的基本增益滤波效应，它可以验证增益引导的脉冲动力学。此外，还详细地数值模拟了时域和频域中的脉冲建立过程，如光谱演化和增益带宽。
