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Theoretical and experimental studies on high-power laser-induced thermal blooming effect in chamber with different gases

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Chinese Physics B 2022年第8期31卷 530-535页

作者： Xiangyizheng Wu Jian Xu Keling Gong Chongfeng Shao Yang Kou Yuxuan Zhang Yong Bo qinjun peng Key Laboratory of Solid-State Laser Technical Institute of Physics and ChemistryChinese Academy of SciencesBeijing 100190China Key Laboratory of Functional Crystal and Laser Technology Technical Institute of Physics and ChemistryChinese Academy of SciencesBeijing 100190China Institute of Optical Physics and Engineering Technology Qilu ZhongkeJinan 250000China University of Chinese Academy of Sciences Beijing 100190China

High-power laser induced thermal blooming effects in a closed chamber with three different gases are investigated theoretically and experimentally in this work. In the theoretical treatment, an incompressible gas turbulent model is *** the numerical simulation the gas refractive index as a function of both the temperature and pressure is taken into consideration. In the experimental study the pump-probe technology is adopted. A high-power 1064-nm fiber laser with maximum output power of 12 k W is used to drive the gas thermal blooming, and a 50-m W high-beam-quality 637-nm laser diode(LD)is used as a probe beam. The influences of the gas thermal blooming in the chamber on the probe beam wavefront and beam quality are analyzed for three different gases of air, nitrogen, and helium, respectively. The results indicate that nitrogen is well suitable for restraining thermal blooming effect for high-power laser. The measured data are in good agreement with the simulated results.

关键词： laser radiation numerical simulation propagation thermal blooming

Pump pulse characteristics of quasi-continuous-wave diode-side-pumped Nd:YAG laser

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Chinese Physics B 2022年第5期31卷 355-359页

作者： Zexin Song Qi Bian Yu Shen Keling Gong Nan Zong Qingshuang Zong Yong Bo qinjun peng Key Laboratory of Solid State Laser Technical Institute of Physics and ChemistryChinese Academy of SciencesBeijing 100190China Key Laboratory of Function Crystal and Laser Technology Technical Institute of Physics and ChemistryChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100190China Southwest Institute of Technical Physics Chengdu 610041China

The influence of pumping laser pulse on the property of quasi-continuous-wave(QCW)diode-side-pumped Nd:YAG laser is investigated theoretically and *** remaining a fixed duty cycle,the average output power increases,and the corresponding thermal focal length shorten with the increase of the pump pulse duration,which attributes to the decrease of the ratio of pulse buildup time to the pulse *** a pump power of 146 W,the laser output power changes from 65.1 W to 81.2 W when the pulse duration is adjusted from 150μs to 1000μs,confirming a significant enhancement of 24.7%.A laser rate equation model incorporating the amplified spontaneous emission is also utilized and numerically solved,and the simulated results agree well with the experimental data.

关键词： pump pulse duration diode-side-pumped pulsed Nd:YAG laser laser rate equation amplified spontaneous emission

The effect of oxygen on the epitaxial growth of diamond

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Journal of Semiconductors 2018年第12期39卷 42-45页

作者： Meng Gong Yanan Chen Wancheng Yu peng Jin Zhanguo Wang Zhimin Wang Shenjin Zhang Feng Yang Fengfeng Zhang qinjun peng Zuyan Xu Key Laboratory of Semiconductor Materials Science Beijing Key Laboratory of Low-Dimensional Semiconductor Materials and Devices Institute of Semiconductors Chinese Academy of Sciences College of Materials Science and Opto-Electronic Technology University of Chinese Academy of Sciences Key Laboratory of Functional Crystal and Laser Technology Technical Institute of Physics and Chemistry Chinese Academy of Sciences

We studied the effect of oxygen on the growth quality of diamond epitaxial layers. After oxygen is added during the growth of the diamond epitaxial layer, as the thickness of the epitaxial layer increases, the full width at half maximum of the rocking curve of the(004) plane of diamond epitaxial layer increases continuously, and, in addition, the intensities of both the Raman peaks and the free exciton emission peaks of the diamond epitaxial layer decrease continuously. These experimental results demonstrate that as the thickness of the diamond epitaxial layer increases, the quality of the diamond epitaxial layer degrades. The strong etching effect of the OH radical groups in the plasma on the diamond epilayers leads to the degradation of their crystallinity.

关键词： diamond ultra-wide bandgap semiconductor MPCVD oxygen effect

Conservation of the particle–hole symmetry in the pseudogap state in optimally-doped Bi_(2)Sr_(2)CuO_(6+δ) superconductor

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Chinese Physics B 2022年第8期31卷 178-182页

作者： Hongtao Yan Qiang Gao Chunyao Song Chaohui Yin Yiwen Chen Fengfeng Zhang Feng Yang Shenjin Zhang qinjun peng Guodong Liu Lin Zhao Zuyan Xu X.J.Zhou National Laboratory for Superconductivity Beijing National Laboratory for Condensed Matter PhysicsInstitute of PhysicsChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Technical Institute of Physics and Chemistry Chinese Academy of SciencesBeijing 100190China Songshan Lake Materials Laboratory Dongguan 523808China Beijing Academy of Quantum Information Sciences Beijing 100193China

The pseudogap state is one of the most enigmatic characteristics in the anomalous normal state properties of the high temperature cuprate superconductors. A central issue is to reveal whether there is a symmetry breaking and which symmetries are broken across the pseudogap transition. By performing high resolution laser-based angle-resolved photoemission measurements on the optimally-doped Bi_(2)Sr_(1.6)La_(0.4)CuO_(6+δ) superconductor, we report the observations of the particle-hole symmetry conservation in both the superconducting state and the pseudogap state along the entire Fermi surface. These results provide key insights in understanding the nature of the pseudogap and its relation with high temperature superconductivity.

关键词： pseudogap symmetry breaking ARPES

High-Energy Tunable 6.5-12 μm Picosecond Mid-Infrared Radiation Generated from Optical Parametric Amplifier Based on LiInSe_(2) Crystal

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激光与光电子学进展 2024年第13期61卷 457-462页

作者： Zhang Jingjing Wang Shilei Yang Feng Wang Shanpeng Gao Hongwei Bo Yong Cui Dafu Tao Xutang peng qinjun Key Lab of Solid State Laser Technical Institute of Physics and ChemistryChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China State Key Laboratory of Crystal Materials Shandong UniversityJinan 250100ShandongChina

We report high-energy tunable 6.5-12 μm ps mid-infrared radiation generation based on OPA pumped using 1064 nm laser in LISe *** simulated the relationship between the idler energy and crystal *** optimum LISe length of 4 mm was used to enhance the idler energy *** a pump energy of ~9.4 mJ, energy levels of ~146 and of ~27 μJ are generated at 6.5 μm and 12 μm, *** highest energy of ~205 μJ is achieved at 8.1 μm at a pump energy of ~19 ***, the angular and spectral width acceptance are measured.

关键词： tunable mid-infrared radiation nonlinear optical crystal LiInSe2 crystal optical parametric amplifier

Emergence of superconductivity from fully incoherent normal state in an iron-based superconductor (Ba_(0.6)K_(0.4))Fe_2As_2

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Science Bulletin 2019年第1期64卷 11-19页

作者： Jianwei Huang Lin Zhao Cong Li Qiang Gao Jing Liu Yong Hu Yu Xu Yongqing Cai Dingsong Wu Ying Ding Cheng Hu Huaxue Zhou Xiaoli Dong Guodong Liu Qingyan Wang Shenjin Zhang Zhimin Wang Fengfeng Zhang Feng Yang qinjun peng Zuyan Xu Chuangtian Chen Xingjiang Zhou Beijing National Laboratory for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences University of Chinese Academy of Sciences Technical Institute of Physics and Chemistry Chinese Academy of Sciences Songshan Lake Materials Laboratory Collaborative Innovation Center of Quantum Matter

In unconventional superconductors, it is generally believed that understanding the physical properties of the normal state is a pre-requisite for understanding the superconductivity mechanism. In conventional superconductors like niobium or lead, the normal state is a Fermi liquid with a well-defined Fermi surface and well-defined quasipartcles along the Fermi surface. Superconductivity is realized in this case by the Fermi surface instability in the superconducting state and the formation and condensation of the electron pairs(Cooper pairing). The high temperature cuprate superconductors, on the other hand, represent another extreme case that superconductivity can be realized in the underdoped region where there is neither well-defined Fermi surface due to the pseudogap formation nor quasiparticles near the antinodal regions in the normal state. Here we report a novel scenario that superconductivity is realized in a system with well-defined Fermi surface but without quasiparticles along the Fermi surface in the normal *** resolution laser-based angle-resolved photoemission measurements have been performed on an optimally-doped iron-based superconductor(Ba_(0.6)K_(0.4))Fe_2As_2. We find that, while sharp superconducting coherence peaks emerge in the superconducting state on the hole-like Fermi surface sheets, no quasiparticle peak is present in the normal state. Its electronic behaviours deviate strongly from a Fermi liquid system. The superconducting gap of such a system exhibits an unusual temperature dependence that it is nearly a constant in the superconducting state and abruptly closes at Tc. These observations have provided a new platform to study unconventional superconductivity in a non-Fermi liquid system.

关键词： (Ba0.6K0.4)Fe2As2 ARPES Superconducting gap Normal state Non-Fermi liquid

垂直腔面发射半导体激光器的特性及其研究现状

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激光与光电子学进展 2018年第5期55卷 49-61页

作者：李玉娇宗楠彭钦军中国科学院理化技术研究所中国科学院固体激光重点实验室北京100190 中国科学院大学北京100049

与传统的边发射半导体激光器相比,垂直腔面发射激光器(VCSEL)具有光束质量好、阈值电流低、易于二维列阵集成和制造成本低廉等优点。近年来,以VCSEL为基础发展起来的电抽运和光抽运垂直外腔面发射激光器(VECSEL),在获得高的输出功率和... 详细信息

与传统的边发射半导体激光器相比,垂直腔面发射激光器(VCSEL)具有光束质量好、阈值电流低、易于二维列阵集成和制造成本低廉等优点。近年来,以VCSEL为基础发展起来的电抽运和光抽运垂直外腔面发射激光器(VECSEL),在获得高的输出功率和光束质量的同时,可以通过在腔内插入光学元件,实现腔内倍频、波长可调谐和锁模等激光技术,在激光领域很有竞争力。本文介绍了面发射半导体激光器的结构、工作原理及性能优势,综述了其在高功率输出、可调谐技术、锁模技术等方面的研究现状与进展,探讨了该类型激光器的发展前景。

关键词：激光器垂直腔面发射半导体激光器电抽运光抽运高功率可调谐技术锁模技术

Temperature-induced Lifshitz transition in topological insulator candidate HfTe_5

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Science Bulletin 2017年第13期62卷 950-956页

作者： Yan Zhang Chenlu Wang Guodong Liu Aiji Liang Lingxiao Zhao Jianwei Huang Qiang Gao Bing Shen Jing Liu Cheng Hu Wenjuan Zhao Genfu Chen Xiaowen Jia Li Yu Lin Zhao Shaolong He Fengfeng Zhang Shenjin Zhang Feng Yang Zhimin Wang qinjun peng Zuyan Xu Chuangtian Chen Xingjiang Zhou Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of Sciences University of Chinese Academy of Sciences Collaborative Innovation Center of Quantum Matter Military Transportation University Technical Institute of Physics and Chemistry Chinese Academy of Sciences

The ongoing discoveries and studies of novel topological quantum materials have become an emergent and important field of condensed matter physics. Recently, Hfres ignited renewed interest as a candidate of a novel topological material. The single-layer Hffes is predicted to be a tWOldimensional large band gap topological insulator and can be stacked into a bulk that may host a temperatureldriven topological phase transition. Historically, Hfres attracted considerable interest for its anomalous transport properties characterized by a peculiar resistivity peak accompanied by a sign reversal carrier type. The origin of the transport anomaly remains under a hot debate. Here we report the first high-resolution laserlbased anglelresolved photoemission measurements on the temperature-dependent electronic structure in Hffes. Our results indicated that a temperature-induced Lifshitz transition occurs in Hffes, which provides a natural understanding on the origin of the transport anomaly in Hffe~. In addition, our observa- tions suggest that Hffes is a weak topological insulator that is located at the phase boundary between weak and strong topological insulators at very low temperature.

关键词： HtTe5 ZrTe5 Lifshitz transition Topological insulators Angle-resolved photoemission spectroscopy(ARPES)

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产生钠导引星星群的钠信标激光合/分束技术

强激光与粒子束 2023年第4期35卷 124-129页

作者：卞奇薄勇左军卫彭钦军中国科学院理化技术研究所激光物理与技术研究中心北京100190 齐鲁中科光物理与工程技术研究院济南250000

研究了脉冲光束的偏振和时序非相干合成技术,通过偏振合束器将两路50 W级500 Hz的589 nm钠信标激光在空间上合为一束光线,成功突破了100 W级μs脉冲全固态钠信标激光输出;利用脉冲激光同步延时器控制两路激光脉冲的时序,使其按先后顺序... 详细信息

研究了脉冲光束的偏振和时序非相干合成技术,通过偏振合束器将两路50 W级500 Hz的589 nm钠信标激光在空间上合为一束光线,成功突破了100 W级μs脉冲全固态钠信标激光输出;利用脉冲激光同步延时器控制两路激光脉冲的时序,使其按先后顺序合成一束脉冲激光,重复频率提升到1 kHz。合束后的激光光束质量M2约为1.41,与单光束的光束质量基本保持一致,光斑抖动性约为40μrad,可满足激光钠导引星自适应光学系统的应用需求。与传统的相干合成方法相比,该偏振和时序非相干合成方案具有结构简单、稳定、效率高的优点,且整个系统无需复杂的相位控制机制,为脉冲激光功率扩展提供了新途径。基于上述技术基础,结合自主提出的精密偏振分光专利技术,在丽江天文台通过一台发射望远镜将四束25 W/束的μs脉冲黄激光发射到钠层,成功产生了四颗钠导引星,这一结果将有助于推动大型地基光学望远镜中多层共轭自适应光学技术的发展。

关键词：钠信标激光非相干光束合成偏振调制时序控制脉冲激光器