高功率激光器在工业应用领域的需求不断增长，提高光-光转化效率是降低其生产制造成本的关键途径。针对提高激光器光-光转化效率所面临的增益介质的热负荷问题，利用锁定波长的969 nm“零声子线”泵浦、自主研制的高性能Yb∶YAG薄片晶体和48冲程泵浦系统等，搭建了高效的连续Yb∶YAG薄片激光器系统，实现了最高输出功率373 W，光-光转化效率可达73.37%。其优异性能为后续开展千瓦级超快Yb∶YAG薄片激光器研究奠定了基础。

采用多级串联的主振荡放大技术，将SESAM锁模的种子光通过多级串联端泵Nd∶YVO₄晶体放大，产生平均功率为148.7 W、重复频率500 kHz~4 MHz、脉冲宽度8 ps的1 064 nm基频光，同时开展了LBO晶体高效率二倍频的研究。通过优化相位匹配，实现了平均功率为95 W的532 nm皮秒激光输出，光-光转换效率达65%，光束质量因子M_X²=1.27/M_Y²=1.42，6 h功率抖动均方根低于0.8%。该绿光皮秒激光系统具有平均功率高、转换效率高、光束质量好、稳定性高、重频可调等优点，可以被作为皮秒激光加工系统的光源，被应用于科学研究和工业加工领域。

We report on a mid-infrared fiber laser that uses a single-walled carbon nanotube saturable absorber mirror to realize the mode-locking operation. The laser generates 3.5 µm ultra-short pulses from an erbium-doped fluoride fiber by utilizing a dual-wavelength pumping scheme. Stable mode-locking is achieved at the 3.5 µm band with a repetition rate of 25.2 MHz. The maximum average power acquired from the laser in the mode-locking regime is 25 mW. The experimental results indicate that the carbon nanotube is an effective saturable absorber for mode-locking in the mid-infrared spectral region.

We experimentally demonstrate an all-fiber supercontinuum source that covers the spectral region ranging from visible to mid-infrared. The ultra-broadband supercontinuum is realized by pumping a cascaded photonic crystal fiber and a highly nonlinear fiber with a 1/1.5 μm dual-band pump source. A maximum output power of 9.01 W is achieved using the system, which is the highest power ever achieved from a supercontinuum source spanning from the visible to mid-infrared.

The simultaneous dual-band pulsed amplification is demonstrated from an Er/Yb co-doped fiber (EYDF), and consequently a high-power all-fiber single-mode 1.0/1.5 μm dual-band pulsed master oscillator power amplifier (MOPA) laser source is realized for the first time, to the best of our knowledge, based on one singlegain fiber. The simultaneous outputs at 1061 and 1548 nm of the laser source have the maximum powers of 10.7 and 25.8 W with the pulse widths of 9.5 ps and 2 ns and the pulse repetition rates of 178 and 25 MHz, respectively. This EYDF MOPA laser source is seeded by two separate preamplifier chains operating at 1.0 and 1.5 μm wavebands. The dependence of the laser output powers on the length of the large-mode area EYDF, the ratio of the powers of the two signals launched into the booster amplifier, and the wavelength of the 1 μm seed signal are also investigated experimentally.