Isolated attosecond pulses (IAPs) are generated via applying amplitude gating on high-order harmonic generation driven by carrier-envelope phase stabilized 5.2 fs pulses with 0.5 mJ pulse energy at 770 nm central wavelength at the Synergetic Extreme Condition User Facility. A continuum ranging from 70 to 100 eV that supports sub-100-attosecond pulse is extracted by Zr foil and Mo/Si multilayer mirror. We demonstrate the characterization of the IAP. The retrieved pulse duration is 86 attoseconds. The developed attosecond laser beamline with repetition rate up to 10 kHz is available for users to conduct attosecond photoelectron spectroscopy researches with a capability of coincidence measurement.amplitude gating coincidence FROG-CRAB high-order harmonic generation isolated attosecond pulses
Chinese Optics Letters
2023, 21(11): 113201
Supercontinuum white laser with large bandwidth and high pulse energy would offer incredible versatility and opportunities for basic science and high technology applications. Here, we report the generation of high-efficiency 2.8-octave-spanning ultraviolet-visible-infrared (UV-Vis-IR) (with 350-2500 nm 25 dB bandwidth) supercontinuum white laser from a single chirped periodically poled lithium niobate (CPPLN) nonlinear crystal via synergic high-harmonic generation (HHG) and self-phase modulation (SPM). The CPPLN exhibits multiple controllable reciprocal-lattice bands to simultaneously support the quasi-phase matching (QPM) for simultaneous broadband 2nd-10th HHG via cascaded three-wave mixing against a broadband fundamental pump laser. Due to the efficient second-order nonlinearity (2nd-NL) up-conversion and significant 3rd-NL SPM effect both in the pump and HHG laser pulses, 350-2500 nm supercontinuum white laser is eventually obtained with 17 μJ per pulse under pump of 45 μJ per pulse mid-infrared femtosecond laser corresponding to an average high conversion efficiency of 37%. Our work opens up a route towards creating UV-Vis-IR all-spectrum white lasers through engineering the synergic action of HHG and SPM effects in nonlinear crystals for applications in ultrafast spectroscopy, single-shot remote sensing, biological imaging, and so on.
2023, 50(11): 1101003
可见光波段激光在科研、工业、医疗以及通信领域应用广泛, 可通过半导体激光器、稀土离子掺杂激光器和非线性频率变换技术产生, 其中可见光稀土离子掺杂激光器近年来受到广泛关注。首先介绍了可见光波段激光的几种典型应用, 然后分析了目前可以产生可见光激光的稀土离子(镨、钕、钐、铕、铽、镝、钬、铒、铥)的发射吸收光谱和激光特性, 最后综述了其中较有潜力的镨离子和铽离子在可见光固体激光器方面的最新研究进展。可见光激光 稀土离子 固体激光器 镨离子 铽离子 visible lasers rare earth ions solid-state lasers praseodymium ion terbium ion
Ultrafast laser oscillators are indispensable tools for diverse applications in scientific research and industry. When the phases of the longitudinal laser cavity modes are locked, pulses as short as a few femtoseconds can be generated. As most high-power oscillators are based on narrow-bandwidth materials, the achievable duration for high-power output is usually limited. Here, we present a distributed Kerr lens mode-locked Yb:YAG thin-disk oscillator which generates sub-50 fs pulses with spectral widths far broader than the emission bandwidth of the gain medium at full width at half maximum. Simulations were also carried out, indicating good qualitative agreement with the experimental results. Our proof-of-concept study shows that this new mode-locking technique is pulse energy and average power scalable and applicable to other types of gain media, which may lead to new records in the generation of ultrashort pulses.
2022, 2(1): 9837892
2022, 51(10): 1014006
超快激光再生放大过程具有复杂的动力学行为, 需要建立模型进行求解和迭代计算。基于改进的 Frantz-Nodvik 方程计算了 Yb:KGW 晶体再生放大器的输出性质, 研究了泵浦强度、晶体长度和泵浦脉宽对放大器输出性能的影响, 同时对不同重复频率再生放大器的输出行为进行了分析。在此基础上设计了再生放大器, 得到了重复频率 1 kHz、单脉冲能量 1 mJ 的激光放大结果, 与理论分析结果符合得较好。该改进的 Frantz-Nodvik 方程对于设计高重复频率、大能量且性能稳定的激光放大器具有参考价值。激光技术 Frantz-Nodvik 方程 掺镱放大器 再生放大 laser techniques Frantz-Nodvik equation ytterbium-doped amplifier regenerative amplifier