We present an effective approach to realize a highly efficient, high-power and chirped pulse amplification-free ultrafast ytterbium-doped yttrium aluminum garnet thin-disk regenerative amplifier pumped by a zero-phonon line 969 nm laser diode. The amplifier delivers an output power exceeding 154 W at a pulse repetition rate of 1 MHz with custom-designed 48 pump passes. The exceptional thermal management on the thin disk through high-quality bonding, efficient heat dissipation and a fully locked spectrum collectively contributes to achieving a remarkable optical-to-optical efficiency of 61% and a near-diffraction-limit beam quality with an M² factor of 1.06. To the best of our knowledge, this represents the highest conversion efficiency reported in ultrafast thin-disk regenerative amplifiers. Furthermore, the amplifier operates at room temperature and exhibits exceptional stability, with root mean square stability of less than 0.33%. This study significantly represents advances in the field of laser amplification systems, particularly in terms of efficiency and average power. This advantageous combination of high efficiency and diffraction limitation positions the thin-disk regenerative amplifier as a promising solution for a wide range of scientific and industrial applications.

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。

设计并制作了一种光纤微悬臂梁传感器，由于悬臂梁在受迫振动过程中不会产生拉伸变形，与四周固定的圆形密闭薄膜相比，会产生更高的声波灵敏度。采用飞秒激光加工制作微悬臂梁薄膜光纤声波传感器，制备出长宽均为500 μm，厚6 μm的微悬臂梁结构。通过实验得到其反射光谱对比度为8.8 dB，自由光谱范围为7.72 nm，理论计算得光纤法布里-珀罗腔长为155.6 μm。研究结果表明，该光纤声波传感器在2 200 Hz处出现明显的共振峰，对应的声压灵敏度为414 mV/Pa，在300 Hz时有最大的灵敏度675 mV/Pa，与普通硅橡胶薄膜声波传感器相比灵敏度显著提高。理论计算硅橡胶微悬臂梁光纤声波传感器的一阶共振频率为198 Hz，与实验测得的共振频率较为接近。同时悬臂梁传感器的声压灵敏度可达675 mV/Pa，声压响应线性度为0.994。

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。

High-power femtosecond mid-infrared (MIR) lasers are of vast importance to both fundamental research and applications. We report a high-power femtosecond master oscillator power amplifier laser system consisting of a single-mode Er:ZBLAN fiber mode-locked oscillator and pre-amplifier followed by a large-mode-area Er:ZBLAN fiber main amplifier. The main amplifier is actively cooled and bidirectionally pumped at 976 nm, generating a slope efficiency of 26.9%. Pulses of 8.12 W, 148 fs at 2.8 μm with a repetition rate of 69.65 MHz are achieved. To the best of our knowledge, this is the highest average power ever achieved from a femtosecond MIR laser source. Such a compact ultrafast laser system is promising for a wide range of applications, such as medical surgery and material processing.

Swept source optical coherence tomography (SS-OCT) is a new noninvasive technique for assessing tissue. Although it has advantages, such as being label-free, noninvasive, and with high resolution, it also has drawbacks: there has been no in-depth research into identifying the driving of swept source. Based on preliminary research, we demonstrate a novel driving modulation method of a fiber Fabry–Perot tunable filter ranging phase adjustable as a tool for making bandwidth compensation of a swept laser source. This novel method is analyzed in detail; a swept laser source with a sweep rate of 100.5 kHz over a range of 152.25 nm and at a center wavelength of 1335.45 nm is demonstrated.

High-power tunable femtosecond mid-infrared (MIR) pulses are of great interest for many scientific and industrial applications. Here we demonstrate a compact fluoride-fiber-based system that generates single solitons tunable from 3 to 3.8 μm. The system is composed of an Er:ZBLAN fiber oscillator and amplifier followed by a fusion-spliced Dy:ZBLAN fiber amplifier. The Er:ZBLAN fiber amplifier acts as a power booster as well as a frequency shifter to generate Raman solitons up to 3 μm. The Dy:ZBLAN fiber amplifier transfers the energy from the residual 2.8 μm radiation into the Raman solitons using an in-band pumping scheme, and further extends the wavelength up to 3.8 μm. Common residual pump radiation and secondary solitons accompanying the soliton self-frequency shift (SSFS) are recycled to amplify Raman solitons, consequently displaying a higher output power and pulse energy, a wider shifting range, and an excellent spectral purity. Stable 252 fs pulses at 3.8 μm with a record average power of 1.6 W and a pulse energy of 23 nJ are generated. This work provides an effective way to develop high-power widely tunable ultrafast single-soliton MIR laser sources, and this method can facilitate the design of other SSFS-based laser systems for single-soliton generation.

利用自行研制的啁啾布拉格光纤光栅(CFBG)刻写系统完成CFBG样品制作，成功应用于光纤锁模振荡器和啁啾脉冲放大(CPA)系统中。振荡器可输出19.4 nm带宽、18 mW平均功率激光，并可压缩至143 fs，经时域展宽、功率放大、时域压缩后，脉冲宽度可至264 fs。实验结果初步证明了国产CFBG在飞秒激光系统应用的可行性。