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light(Science & Applications) 2024年第2期13卷 354-365页

作者： Yaoxiang liu Fukang Yin Tie-Jun Wang Yuxin Leng ruxin li Zhizhan Xu See Leang Chin State Key Laboratory of High Field Laser Physics Shanghai Institute of Optics and Fine Mechanics and CAS Center for Excellence in Ultra-intense Laser ScienceChinese Academy of SciencesShanghaiChina Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijingChina Centre d’Optique Photonique et Laser(COPL)and Département de physiquede génie physique et d’optiqueUniversitéLavalQuébecQuébecCanada

Supercontinuum(SC)light source has advanced ultrafast laser spectroscopy in condensed matter science,biology,physics,and *** to the frequently used photonic crystal fibers and bulk materials,femtosecond laser filamentation in gases is damage-immune for supercontinuum generation.A bottleneck problem is the strong jitters from filament induced self-heating at kHz repetition rate *** demonstrated stable kHz supercontinuum generation directly in air with multiple mJ level pulse *** was achieved by applying an external DC electric field to the air plasma *** pointing jitters of the 1 kHz air filament induced SC light were reduced by more than 2 *** stabilized high repetition rate laser filament offers the opportunity for stable intense SC generation and its applications in air.

关键词： intense repetition light

lightning in a Forest (Wild) Fire: Mechanism at the Molecular Level

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Atmospheric and Climate Sciences 2024年第1期14卷 128-135页

作者： See Leang Chin Xueliang Guo Harmut Schroeder Huanbin Xu Tie-Jun Wang ruxin li Weiwei liu Department of Physics and Center for Optics Photonics and Lasers (COPL) Laval University Quebec Canada Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China Max Planck Institute of Quantum Optics Garching Germany State Key Laboratory of High Field Laser Physics Shanghai Institute of Optics and Fine Mechanics Chinese Academy of Sciences Shanghai China Institute of Modern Optics Nankai University Tianjin China

The mechanism of lightning that ignites a forest fire and the lightning that occurs above a forest fire are explained at the molecular level. It is based on two phenomena, namely, internal charge separation inside the atmospheric cloud particles and the existence of a layer of positively charged hydrogen atoms sticking out of the surface of the liquid layer of water on the surface of rimers. Strong turbulence-driven collisions of the ice particles and water droplets with the rimers give rise to breakups of the ice particles and water droplets into positively and negatively charged fragments leading to charge separation. Hot weather in a forest contributes to the updraft of hot and humid air, which follows the same physical/chemical processes of normal lightning proposed and explained recently[1]. lightning would have a high probability of lighting up and burning the dry biological materials in the ground of the forest, leading to a forest (wild) fire. The burning of trees and other plants would release a lot of heat and moisture together with a lot of smoke particles (aerosols) becoming a strong updraft. The condition for creating lightning is again satisfied which would result in further lightning high above the forest wild fire.

关键词： Forest Wild Fire lightning Molecular Level

从超强超短激光的脉冲前沿畸变到X形光波包的群速度控制

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激光与光电子学进展 2024年第5期61卷 1-12页

作者：李朝阳冷雨欣李儒新张江实验室上海201210 中国科学院上海光学精密机械研究所强场激光物理国家重点实验室上海201800 上海科技大学上海201210

超强超短激光在空间上具有大口径、在时间上具有短脉冲,因此极易产生时空耦合效应,例如脉冲前沿畸变,使得脉冲前沿和相位前沿发生时空分离,通常表现为脉冲前沿倾斜或弯曲,不利于获得预期的高聚焦光强。但当这种脉冲前沿畸变(控制)用于产... 详细信息

超强超短激光在空间上具有大口径、在时间上具有短脉冲,因此极易产生时空耦合效应,例如脉冲前沿畸变,使得脉冲前沿和相位前沿发生时空分离,通常表现为脉冲前沿倾斜或弯曲,不利于获得预期的高聚焦光强。但当这种脉冲前沿畸变(控制)用于产生X形光波包时,却增加了一维全新的自由度,实现了光波包群速度和群加速度的自由控制,可获得超光速、亚光速、加速、减速,甚至动态可控的群速度。通过综述脉冲前沿畸变(控制)在超强超短激光中的不良影响和在X形光波包中的特殊效果,旨在为同一光学现象在不同研究方向间的交叉应用提供些许思考。

关键词：时空耦合脉冲前沿相位前沿 X形光波包群速度群加速度

基于h-BN的方向依赖高次谐波产生(特邀)

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光子学报 2024年第6期53卷 101-109页

作者：郑文洋刘灿东白亚刘鹏李儒新中国科学院上海光学精密机械研究所强场激光物理国家重点实验室上海201800 中国科学院大学北京100049 张江实验室上海201210

利用紧束缚电子能带结构并结合求解两能带半导体Bloch方程的方法,研究了单层h-BN的高次谐波产生过程。结果显示平行于驱动光偏振方向的谐波分量在截止区表现出异常的晶格取向依赖关系,当光子能量超过7.31 eV时,奇次谐波的取向依赖相对... 详细信息

利用紧束缚电子能带结构并结合求解两能带半导体Bloch方程的方法,研究了单层h-BN的高次谐波产生过程。结果显示平行于驱动光偏振方向的谐波分量在截止区表现出异常的晶格取向依赖关系,当光子能量超过7.31 eV时,奇次谐波的取向依赖相对于较低级次的奇次谐波取向依赖表现出明显的30°角度偏移。确定了能够发生偏移的那些谐波光子能量与布里渊区M点处的载流子动力学相关。进一步的时频分析表明,当驱动光偏振沿zigzag方向时,截止区谐波仅在特定极性的激光半周期内产生,这导致了zigzag方向谐波的急剧减弱,从而造成了截止区晶格取向分布的偏移。这一现象对利用高次谐波光谱重建电子能带结构具有重要意义。

关键词：高次谐波二维材料强场动态方向依赖角度偏移

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全光逆康普顿散射源

光学学报 2024年第4期44卷 78-89页

作者：魏见萌夏长权冯珂张虹姜海葛彦杰王文涛冷雨欣李儒新中国科学技术大学物理学院安徽合肥230026 中国科学院上海光学精密机械研究所强场激光物理国家重点实验室中国科学院超强激光科学卓越中心上海201800 扬州大学物理科学与技术学院江苏扬州225009 上海科技大学物质科学与技术学院上海200031

逆康普顿散射源是利用高能电子束和强激光对撞产生高能辐射的光源。传统电子加速器作为电子源的逆康普顿散射源体积庞大,难以推广。而新型的激光等离子体电子加速器具有更高的加速梯度,具备小型化的发展潜力。全光逆康普顿散射源就是一... 详细信息

逆康普顿散射源是利用高能电子束和强激光对撞产生高能辐射的光源。传统电子加速器作为电子源的逆康普顿散射源体积庞大,难以推广。而新型的激光等离子体电子加速器具有更高的加速梯度,具备小型化的发展潜力。全光逆康普顿散射源就是一种基于激光等离子体电子加速器实现的小型化高能辐射源,具有更短脉宽、更高亮度的辐射输出,应用前景十分广阔。首先,总结了全光逆康普顿散射源在提高亮度、能量和单能性等方面的优化研究进展,并分析了设计重点;最后,介绍了全光逆康普顿散射源在基础科学研究、工业和生物医学领域的典型应用。

关键词：超快激光激光等离子体电子加速全光逆康普顿散射源新型辐射源

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耕作方式对土壤中微生物残体的影响研究进展

福建农业学报 2024年第2期39卷 237-242页

作者：李如欣高其松于迎鑫吕艺韩惠芳作物生物学国家重点实验室/土肥资源高效利用国家工程实验室/山东农业大学农学院山东泰安271018

微生物残体的续埋效应在农田生态系统中对土壤有机碳(SOC)的贡献超过了50%。合理的耕作方式能通过影响土壤微生物群落与团聚体,促进微生物残体在土壤中的积累。因此,研究微生物残体的作用机制,对分析长期高效的农田耕作措施对SOC的固持... 详细信息

微生物残体的续埋效应在农田生态系统中对土壤有机碳(SOC)的贡献超过了50%。合理的耕作方式能通过影响土壤微生物群落与团聚体,促进微生物残体在土壤中的积累。因此,研究微生物残体的作用机制,对分析长期高效的农田耕作措施对SOC的固持作用至关重要。本文综述微生物残体对SOC的贡献途径与大小、耕作方式对SOC和微生物残体的影响、耕作方式影响微生物残体的原因,分析耕作方式影响微生物残体调控SOC含量的作用机制,为农田固碳提供依据。

关键词：耕作方式微生物残体土壤有机碳

基于百太瓦级激光系统驱动的高能量13 nm波段高次谐波产生

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光学学报 2024年第2期44卷 221-228页

作者：高记星娄智远杨帆杨晓骏许毅冷雨欣郑颖辉曾志男李儒新中国科学院上海光学精密机械研究所强场激光物理国家重点实验室上海201800 中国科学院大学材料科学与光电工程中心北京100049 张江实验室上海201210

利用百太瓦级激光系统在氖气(Ne)中得到基于高次谐波产生的极紫外脉冲。通过松聚焦结构在13 nm波段产生单级次单脉冲能量为13.5 nJ(13.1 nm波长)和11.1 nJ(13.5 nm波长)的高次谐波辐射,转换效率为3.6×10^(-7)和3.0×10^(-7),谐波发散... 详细信息

利用百太瓦级激光系统在氖气(Ne)中得到基于高次谐波产生的极紫外脉冲。通过松聚焦结构在13 nm波段产生单级次单脉冲能量为13.5 nJ(13.1 nm波长)和11.1 nJ(13.5 nm波长)的高次谐波辐射,转换效率为3.6×10^(-7)和3.0×10^(-7),谐波发散角的半高全宽为0.32 mrad和0.33 mrad。对含时薛定谔方程进行数值求解,得到单原子偶极发射谱,结合麦克斯韦方程组模拟传播效应,同时考虑气体对谐波的吸收效应,理论模拟得到的信号强度随气压和光强的变化趋势与实验结果基本符合。实现相位匹配的谐波光束质量很好,纵向空间分布为高斯型。结合相位匹配条件和空间分布的分析得到了目前激光参数下的最优相位匹配条件。这种基于高次谐波机制的高能量相干极紫外光源在作为自由电子激光的种子光源以及超快非线性实验和半导体工业检测等方面具有广阔的应用前景。

关键词：极紫外高次谐波相位匹配空间分布

Generating a tunable narrow electron beam comb via laser-driven plasma grating

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Matter and Radiation at Extremes 2023年第6期8卷 4-10页

作者： Hetian Yang Jingwei Wang Shixia Luan Ke Feng Wentao Wang ruxin li College of Science University of Shanghai for Science and TechnologyShanghai 200093People’s Republic of China State Key Laboratory of High Field Laser Physics and CAS Center for Excellence in Ultra-Intense Laser Science Shanghai Institute of Optics and Fine Mechanics(SIOM)Chinese Academy of Sciences(CAS)Shanghai 201800People’s Republic of China School of Physical Science and Technology ShanghaiTech UniversityShanghai 200031People’s Republic of China

We propose a novel approach for generating a high-density,spatially periodic narrow electron beam comb(EBC)from a plasma grating induced by the interference of two intense laser pulses in subcritical-density *** employ particle-in-cell(PIC)simulations to investigate the effects of cross-propagating laser pulses with specific angles overlapping in a subcritical *** overlap results in the formation of a transverse standing wave,leading to a spatially periodic high-density modulation known as a plasma *** electron density peak within the grating can reach several times the background plasma *** charge imbalance between electrons and ions in the electron density peaks causes mutual repulsion among the electrons,resulting in Coulomb expansion and acceleration of the *** a result,some electrons expand into vacuum,forming a periodic narrow EBC with an individual beam width in the nanoscale *** further explore the formation of the nanoscale EBC,we conduct additional PIC simulations to study the dependence on various laser ***,our proposed method offers a promising and controlled approach to generate tunable narrow EBCs with high density.

关键词： tunable narrow beam

A 100-PW compressor based on single-pass single-grating pair

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High Power Laser Science and Engineering 2023年第1期11卷 26-37页

作者： Shuman Du Xiong Shen Wenhai liang Peng Wang Jun liu ruxin li State Key Laboratory of High Field Laser Physics and CAS Center for Excellence in Ultra-intense Laser Science Shanghai Institute of Optics and Fine MechanicsChinese Academy of SciencesShanghaiChina Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijingChina Zhangjiang Laboratory ShanghaiChina

A multistep pulse compressor(MPC)based on a single-pass single-grating pair(SSGP)is proposed to simplify the entire multi-petawatt(PW)*** one grating pair with relatively long perpendicular distance is used to generate the same amount of spectral chirp compared with a four-grating main *** SSGP compressor induces the largest spatial chirp,it can introduce the best beam-smoothing effect to the laser beam on the last *** considering the diffraction loss of only two gratings,the total compression efficiency of the SSGP compressor is even larger than that of a four-grating main ***,the wavefront aberration induced by the SSGP compressor can be better compensated by using deformable mirrors;however,it is difficult or complicated to be well compensated in a four-grating *** 50-100 PW laser pulses can be obtained using this SSGP-based multistage-smoothing MPC with a single laser beam.

关键词： beam smoothing multistep pulse compressor petawatt single-grating-pair compressor

Goldilocks focal zone in femtosecond laser ignition of lean fuels

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Science China(Technological Sciences) 2022年第7期65卷 1537-1544页

作者： ZANG HongWei li HeLong liANG TianFeng CHEN ShanMing ZHANG Wei FU Yao XU Huailiang li ruxin State Key Laboratory of Integrated Optoelectronics College of Electronic Science and EngineeringJilin UniversityChangchun 130012China Institute of Atomic and Molecular Physics Jilin UniversityChangchun 130012China CAS Center for Excellence in Ultra-Intense Laser Science Shanghai 201800China State Key Laboratory of High Field Laser Physics Shanghai Institute of Optics and Fine MechanicsCASShanghai 201800China School of Physical Science and Technology Shanghai Tech UniversityShanghai 201210China

Laser ignition of lean fuels offers a promising route for green combustion with high combustion efficiency and low exhaust emissions. The fundamental limitations which apply to femtosecond laser ignition(fs-li) of lean fuels are the inferior energy deposition and low thermodynamic temperature. However, it was discovered recently that the fs laser filamentation can induce 100% success rate of fs-li with ultralow sub-m J minimum ignition energy, exhibiting distinct contrast to the general understanding that it is hard to achieve fs-li. The present contribution examines the extent to which the minimum ignition energies depend on filamentation formation, and explores the key factors for the success of fs-li. We perform fs-li of a lean-fuel CH;/air mixture using a femtosecond near-infrared(~40 fs, 800 nm) pulse at different external focal conditions, and find a Goldilocks focal zone to facilitate fs-li. In this special zone, a crucial balance between the length of igniting “line” kernel and the plasma density of the fs laser filament is achieved, which determines not only the total amount of resultant OH radicals, but also their distribution along the plasma filament. Our finding provides a viable strategy with clear guidelines for fs-li, and also opens up an avenue of exploring unprecedented ultrafast ignition dynamics after fs-laser-fuel interactions towards gaining deeper insights into reaction intermediates and combustion processes.

关键词： femtosecond laser laser ignition lean fuels laser filament laser spectroscopy