Shuailin Liu 1,2,3Bin Zhang 1,2,3,*Yuanzhuang Bu 1,2,3Desheng Zhao 1,2,3[ ... ]Jing Hou 1,2,3,*
Author Affiliations
Abstract
1 College of Advanced Interdisciplinary Studies, National University of Defense Technology, Changsha, China
2 Nanhu Laser Laboratory, National University of Defense Technology, Changsha, China
3 Hunan Provincial Key Laboratory of High Energy Laser Technology, Changsha, China
We report a Yb-doped all-fiber laser system generating burst-mode pulses with high energy and high peak power at a GHz intra-burst repetition rate. To acquire the uniform burst envelope, a double-pre-compensation structure with an arbitrary waveform laser diode driver and an acoustic optical modulator is utilized for the first time. The synchronous pumping is utilized for the system to reduce the burst repetition rate to 100 Hz and suppress the amplified spontaneous emission effect. By adjusting the gain of every stage, uniform envelopes with different output energies can be easily obtained. The intra-burst repetition rate can be tuned from 0.5 to 10 GHz actively modulated by an electro-optic modulator. Optimized by timing control of eight channels of analog signal and amplified by seven stages of Yb-doped fiber amplifier, the pulse energy achieves 13.3 mJ at 0.5 ns intra-burst pulse duration, and the maximum peak power reaches approximately 3.6 MW at 48 ps intra-burst pulse duration. To the best of our knowledge, for reported burst-mode all-fiber lasers, this is a record for output energy and peak power with nanosecond-level burst duration, and the widest tuning range of the intra-burst repetition rate. In particular, this flexibly tunable burst-mode laser system can be directly applied to generate high-power frequency-tunable microwaves.
burst-mode laser fiber laser high peak power high pulse energy High Power Laser Science and Engineering
2023, 11(6): 06000e81
Desheng Zhao 1,2,3Bin Zhang 1,2,3,*Xiran Zhu 1,2,3Shuailin Liu 1,2,3[ ... ]Jing Hou 1,2,3,*
Author Affiliations
Abstract
1 College of Advanced Interdisciplinary Studies, National University of Defense Technology, Changsha, China
2 Nanhu Laser Laboratory, National University of Defense Technology, Changsha, China
3 Hunan Provincial Key Laboratory of High Energy Laser Technology, Changsha, China
We propose a 2.1 μm high-energy dissipative soliton resonant (DSR) fiber laser system based on a mode-locked seed laser and dual-stage amplifiers. In the seed laser, the nonlinear amplifying loop mirror technique is employed to realize mode-locking. The utilization of an in-band pump scheme and long gain fiber enables effectively exciting 2.1 μm pulses. A section of ultra-high numerical aperture fiber (UHNAF) with normal dispersion and high nonlinearity and an output coupler with a large coupling ratio are used to achieve a high-energy DSR system. By optimizing the UHNAF length to 55 m, a 2103.7 nm, 88.1 nJ DSR laser with a 3-dB spectral bandwidth of 0.48 nm and a pulse width of 17.1 ns is obtained under a proper intracavity polarization state and pump power. The output power and conversion efficiency are 0.233 W and 4.57%, respectively, both an order of magnitude higher than those of previously reported holmium-doped DSR seed lasers. Thanks to the high output power and nanosecond pulse width of the seed laser, the average power of the DSR laser is linearly scaled up to 50.4 W via a dual-stage master oscillator power amplifier system. The 3-dB spectral bandwidth broadens slightly to 0.52 nm, and no distortion occurs in the amplified pulse waveform. The corresponding pulse energy reaches 19.1 μJ, which is the highest pulse energy in a holmium-doped mode-locked fiber laser system to the best of our knowledge. Such a 2.1 μm, high-energy DSR laser with relatively wide pulse width has prospective applications in mid-infrared nonlinear frequency conversion.
High Power Laser Science and Engineering
2023, 11(1): 01000e12
西安工业大学 光电工程学院，陕西 西安 710021
高脉冲能量和窄脉冲宽度的激光放大器可以应用在诸多领域，例如激光加工、激光医疗美容和激光雷达。种子源激光器与行波放大结构相结合的主振荡功率放大（MOPA）技术，既能保证输出的脉冲激光相关特性（如脉宽和重复频率等）与种子源特性一致，又能实现激光输出能量的放大。因此MOPA技术成为激光放大器工程应用中的主要技术。本课题针对医疗美容对亚纳秒级大能量激光放大器的需求，研制了一台基于亚纳秒微片固体激光器的激光放大器。首先，采用亚纳秒被动调Q微片固体激光器作为种子源。种子源激光器在重复频率为10 Hz，脉冲宽度为487.3 ps时输出能量为190 μJ的1064 nm种子光。然后，利用自制的两个氙灯泵浦Nd: YAG模块作为主放大器对亚纳秒激光脉冲能量进行放大，对放大过程自激振荡产生的能量实现了抑制，有效地提高了放大过程中的能量转换效率。最终，得到了波长1064 nm和532 nm可切换输出，在重复频率为10 Hz时，获得了脉冲宽度496.4 ps，脉冲能量561 mJ@1064 nm，330 mJ@532 nm，能量稳定性2%且光斑均匀的亚纳秒激光输出。
亚纳秒 高能量 氙灯泵浦 波长可切换 放大器 sub-nanosecond high pulse energy xenon lamp pumping wavelength switchable amplifier 红外与激光工程
2022, 51(4): 20210200
Author Affiliations
Abstract
1 Key Laboratory of Advanced Optical Precision Manufacturing Technology of Guangdong Higher Education Institutes, Shenzhen Technology University, Shenzhen 518118, China
2 Key Laboratory of Optoelectronic Devices and System of Ministry of Education, College of Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China
3 Shenzhen Key Laboratory of Laser Engineering, Shenzhen University, Shenzhen 518060, China
4 Key Laboratory of Advanced Optical Precision Manufacturing Technology of Guangdong Higher Education Institutes, Shenzhen Technology University, Shenzhen 518118, China
We report on mode-locked thulium-doped fiber lasers with high-energy nanosecond pulses, relying on the transmission in a semiconductor saturable absorber (SESA) and a carbon nanotube (CNTs-PVA) film separately. A section of an SMF–MMF–SMF structure multimode interferometer with a transmission peak wavelength of ～2003 nm was used as a wavelength selector to fix the laser wavelength. When the SESA acted as a saturable absorber (SA), the mode-locked fiber laser had a maximum output power of ～461 mW with a pulse energy of ～0.14 μJ and a pulse duration of ～9.14 ns. In a CNT-film-based mode-locked fiber laser, stable mode-locked pulses with the maximum output power of ～46 mW, pulse energy of ～26.8 nJ and pulse duration of ～9.3 ns were obtained. To the best of our knowledge, our experiments demonstrated the first 2 μm region ‘real’ SA-based dissipative soliton resonance with the highest mode-locked pulse energy from a ‘real’ SA-based all-fiberized resonator.
high pulse energy mode-locking nanosecond pulse Tm-doped fiber laser High Power Laser Science and Engineering
2020, 8(2): 02000e14
介绍了重频为400 KHz，脉冲宽度为960 ps输出的高脉冲能量的亚纳秒掺镱光纤激光器。该激光器采用全光纤主振荡功率放大(MOPA)结构，种子源使用的是实验室自制的频率为400 kHz，脉宽为940 ps，输出功率为100 mW的掺镱光纤激光器，通过6个10 W多模激光抽运将种子光放大到8.9 W平均功率输出，相应的单脉冲能量达到22 μJ，峰值功率达到23 kW，输出激光中心波长为1064.5 nm。该亚纳秒、高能量脉冲激光器可广泛用于材料加工，激光测距，激光雷达等领域。
激光器 光纤激光器 光纤放大器 高脉冲能量 亚纳秒脉冲 中国激光
2013, 40(12): 1202003
为了得到高单脉冲能量的百皮秒激光脉冲，采用自制的被动锁模掺镱光纤激光器获得了100ps的激光脉冲输出，在此基础上采用两级全光纤结构主振荡功率放大器进行功率放大，其中预放大级采用7μm纤芯的双包层掺镱光纤做增益介质，得到平均功率160mW的稳定脉冲输出；主放大级采用20μm纤芯的双包层掺镱光纤做增益介质，在抽运功率逐步增加到35.37W时，输出功率达到了16.60W，相应的单脉冲能量为1.63μJ，峰值功率为16.61kW。此外，主放大级输出的激光通过自制的模场转换器与光子晶体光纤（纤芯4.6μm）成功熔接，得到了2.85W的白光超连续光谱，光谱波长覆盖了600nm~1700nm的检测范围。结果表明，此激光可用于超连续谱光源的产生。
光纤光学 主振荡功率放大器 高脉冲能量 白光超连续谱 fiber optics master oscillator power amplifier high pulse energy white light supercontinuum
1 北京工业大学激光工程研究院， 北京 100124
2 天津大学化工学院， 天津 300072
报道了石墨烯材料作为可饱和吸收体的被动锁模、被动调Q掺镱全光纤激光器。采用环形腔结构，在抽运功率为1.2 W时，有稳定的重复频率为1.04 MHz的自锁模脉冲发生，平均输出功率为46 mW；当抽运功率增加到2.3 W 时，平均输出功率为170 mW，相应的单脉冲能量高达163 nJ，脉冲宽度约为680 ps。采用线形腔结构，实现了石墨烯被动调Q激光脉冲输出，其重复频率在140~257 kHz可调，最窄激光脉冲宽度为70 ns，最大平均功率为12 mW，相应最大单脉冲能量为46 nJ。
激光器 光纤激光器 高脉冲能量 石墨烯 锁模 被动调Q
军械工程学院 光学与电子工程系， 石家庄 050003
为了研究双光路合成系统中的重要参量与远场光束合成效果的关系，采用理论计算与仿真验证相结合的方法，用ZEMAX软件对双光路合成系统进行了仿真。由理论计算结果与仿真结果比较可知，两者在光束重合程度、重合光斑半径上的相关数据基本吻合。结果表明，当双光路合成系统的参量选定时，利用这种理论计算方法可以很好地计算出远场光束的合成情况。这一结果为双光路合成系统中重要参量值的设置提供了很好的依据。
激光光学 光束合成 ZEMAX软件 高重频 高脉冲能量 laser optics beams combination ZEMAX software high repition frequency high pulse energy
1 中国工程物理研究院应用电子技术研究所,四川 绵阳 621900
2 浙江大学 现代光学仪器国家重点实验室,浙江 杭州 310027
使用最高重复频率可达1000 Hz的脉冲激光二极管抽运的电光调Q单纵模激光器作为种子源,经过两级预放大器和两级主功率放大器后获得高重复频率高能量的激光输出。然后使用此光源对由芯径为1 mm和400 μm的石英光纤组合而成的大口径锥度光纤固体相位共轭镜在重复频率分别为1000,500和400 Hz情况下的受激布里渊散射反射率进行了详细的实验研究,并分别得到33.3%,41.2%和50.7%的最高反射率。实现了固体相位共轭镜在高重复频率大能量条件下大于50%的受激布里渊散射反射率。在重复频率为400 Hz时,激光脉冲宽度从24 ns压缩到6 ns,压缩比为4:1,且脉冲光滑无调制。
激光器 高重复频率 大能量 相位共轭镜 锥度光纤
1 军械工程学院，河北 石家庄 050003
2 空军石家庄航空四站装备修理厂， 河北 石家庄 050003
为了进行对CCD探测器的损伤机理的探索研究，提出了采用双光束合成器件产生混合频率激光的原理与方法.利用Zemax软件模拟了双光束合成器件，同时对远场光斑进行了采集.基于热传导和热弹性力学的基本关系式建立了混合频率激光辐照CCD探测器遮光铝膜层的热力耦合数学物理模型，对热传导方程和应力平衡方程进行了半解析求解,计算得到混合频率激光辐照CCD探测器的遮光铝膜层的瞬态温度场和环向热应力场,并通过数值仿真比较了不同工作模式激光光源对CCD的损伤效果.
激光损伤 面阵CCD 光束合成 高重频 高脉冲能量 laser induced damage array CCD beams combination high repetition frequency high pulse energy
