Gallium sulfide (GaS), with a hexagonal structure, has received extensive attention due to its graphene-like structure and derived optical properties. Here, high-quality GaS was obtained via chemical vapor synthesis and then prepared as a saturable absorber by the stamp-assisted localization-transfer technique onto fiber end face. The stability of the material and the laser damage threshold are maintained due to the optimized thickness and the cavity integration form. The potential of the GaS for nonlinear optics is explored by constructing a GaS-based Erbium-doped mode-locked fiber laser. Stable femtosecond (~448 fs) mode-locking operation of the single pulse train is achieved, and the robust mode-locked operation (>30 days) was recorded. Experimental results show the potential of GaS for multi-functional ultrafast high-power lasers and promote continuous research on graphene-like materials in nonlinear optics and photonics.

The phase noise and relative intensity noise (RIN) of an all-fiber high-power harmonic mode-locked Mamyshev oscillator (MO) are experimentally investigated. Through characterize in detail the integrated time jitter (TJ) and RIN under different output power of each order of harmonic mode-locking, it is found that the integrated TJ/RIN gradually degraded with increasing the output power. In the meantime, the noise performance can be improved with increasing the repetition rate at a specific pump power. In addition, it is also found in the experiment that the stimulated Raman scattering (SRS) effect deteriorates the phase noise and RIN of the laser output considerably. At the highest output power of 3.62 W, the integrated TJ/RIN reduces from 2.88 ps/0.36% to 2.39 ps/0.24% after spectrally filtering out the SRS components. However, the autocorrelation trace of the compressed pulse shows no obvious change with and without the SRS components.

A highly stable figure-9 Yb-doped fiber laser with all polarization-maintaining (PM) double-cladding fiber is demonstrated. Through leveraging the saturable absorption effect of a nonlinear amplifying loop mirror, both the Q-switched and mode-locked operation are realized by adjusting the pump power. With increasing the pump power from the threshold to the maxima, the repetition rate of the Q-switched pulses is linearly increased from 14.9 kHz to 138.0 kHz with the pulse duration accordingly reduced from 3.9 µs to 970 ns. The corresponding maximum average power and pulse energy are respectively 2.34 W and 17 µJ, which are more than ten times larger than the common material-based Q-switched all-fiber lasers. In addition, in the process of increasing and decreasing the pump power, an optical bistability that manifested as a significant power jumping effect is observed, while its effect on the pulse repetition rate and duration is trivial. Whereas for the single pulse mode-locked operation, a maximum output power of 56.3 mW with a fundamental repetition rate of 12.5 MHz is realized, corresponding to a pulse energy of 4.5 nJ. To the best of our knowledge, it is much higher than the most of previous works concerning figure-9 all-PM-fiber lasers of which the emitted pulse energy is generally less than 1 nJ. After being compressed by a pair of diffraction grating, a minimum pulse width of 378 fs and a maximum peak power of 9.76 kW are respectively obtained. In addition, through characterizing the spectral and temporal properties of the laser source, the excellent stability of both the Q-switched and mode-locked operations is verified.

过渡金属硫代亚磷酸盐MnPS₃是三元含磷二维材料, 具有新颖的光电特性. 采用化学气相传输方法生长MnPS₃单晶, 结合机械剥离方法制备可饱和吸收体光纤调制器件. 以MnPS₃可饱和吸收体构建掺铒光纤环形激光器, 实现脉冲间隔为196.1 ns, 脉冲宽度为3.8 ns, 最高输出功率为27.2 mW, 1565.19 nm和1565.63 nm双波长锁模脉冲激光输出, 实现280 h以上高稳定自启动双波长锁模输出.