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Optoelectronics Letters 2024年第8期20卷 460-471页

作者： LI Zhihan HE Wei LI Shaode Key Laboratory of the Ministry of Education for Optoelectronic measurement Technology and Instrument Beijing Information Science and Technology University Beijing Laboratory of Optical Fiber Sensing and System Beijing Information Science and Technology University

Mid-infrared wavelength switchable and dual-wavelength random laser output has many potential applications. A polarization-maintaining random fiber Bragg grating(PMRFBG) array based on the photonic localization effect of longitudinal invariant transverse disorder in fiber structure is proposed, which can be used as random feedback of dual-wavelength and wavelength switchable output of random fiber laser(RFL). The random fiber Bragg grating(RFBG) array was designed on the panda-type polarization-maintaining fiber(PMF), and the two center wavelengths were 2 151.60 nm and 2 152.22 nm, respectively. The RFBG array was designed on the bow tie-type PMF, and the two center wavelengths were obtained, which were 2 153.08 nm and 2 153.96 nm, respectively. The RFBG array with a center wavelength of 2 139.27 nm was designed on single-mode fiber(SMF). The length of individual fiber Bragg grating(FBG) and PMRFBG, the refractive index modulation depth, the number of cascaded gratings, and the distance between gratings have different effects on the full width at half maximum(FWHM) and reflectance of the RFBG and PMRFBG array, but not on the central wavelength, as obtained by simulation using the transmission matrix method. The designed PMRFBG array provides theoretical support for the design of the feedback mechanism of RFL.

关键词： A

Welding depth measurement for different mode lasers using optical coherence tomography

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Chinese Optics Letters 2024年第1期22卷 41-46页

作者：谢冠明王三宏张跃强李由胡彪傅愉于起峰 Institute of Intelligent Optical measurement and Detection Shenzhen UniversityShenzhen 518060China College of Physics and Optoelectronic Engineering Shenzhen UniversityShenzhen 518060China Shenzhen Sincevision Technology Co. Ltd.Shenzhen 518055China National Key Laboratory of Human Factors Engineering China Astronaut Research and Training CenterBeijing 100094China College of Aerospace Science and Engineering National University of Defense TechnologyChangsha 410073China

Optical coherence tomography(OCT)allows a direct and precise measurement of laser welding depth by coaxially measuring the keyhole depth and can be used for process monitoring and *** OCT measurement was taken during single-beam laser welding,the keyhole instability of aluminum welding resulted in highly scattered OCT data and complicated the welding depth extraction *** a combination of an inner core beam and an outer ring beam,a novel adjustable ring mode(ARM)laser for producing a stable keyhole was applied to the OCT *** ARM laser power arrangements were conducted on aluminum and *** results indicated that the ring beam greatly improved the stability of the core beam-induced keyhole,and smooth welding depth can be extracted from the concentrated OCT data.

关键词： optical coherence tomography adjustable ring mode laser laser welding welding depth

Strong-field photoelectron holography in the subcycle limit

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Light(Science & Applications) 2024年第6期13卷 1032-1040页

作者： Tsendsuren Khurelbaatar Jaewuk Heo ShaoGang Yu XuanYang Lai XiaoJun Liu Dong Eon Kim center for Attosecond Science and Technology Department of PhysicsPohang University of Science and TechnologyPohangGyeongbuk37673Korea Max Planck POSTECH/KOREA Research Initiative PohangGyeongbuk37673Korea State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics Wuhan Institute of Physics and MathematicsInnovation Academy for Precision Measurement Science and TechnologyChinese Academy of Sciences430071WuhanChina Wuhan Institute of Quantum Technology 430206WuhanChina

Strong-field photoelectron holography is promising for the study of electron dynamics and structure in atoms and molecules,with superior spatiotemporal resolution compared to conventional electron and X-ray ***,the application of strong-field photoelectron holography has been hindered by inter-cycle interference from multicycle ***,we address this challenge by employing a near-single-cycle field to suppress the inter-cycle *** observed and separated two distinct holographic patterns for the first *** measurements allow us not only to identify the Gouy phase effect on electron wavepackets and holographic patterns but also to correctly extract the internuclear separation of the target molecule from the holographic *** work leads to a leap jump from theory to application in the field of strong-field photoelectron holography-based ultrafast imaging of molecular structures.

关键词： photoelectron holographic cycle

Fixed-Time Consensus-Based Nash Equilibrium Seeking

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IEEE/CAA Journal of Automatica Sinica 2024年第1期11卷 267-269页

作者： Mengwei Sun Jian Liu Lu Ren Changyin Sun the Institutes of Physical Science and Information Technology Anhui UniversityHefei 230601China IEEE the School of Automation and the Key Laboratory of measurement and Control of Complex System of Engineering Ministry of EducationSoutheast UniversityNanjing 210096China the School of Artificial Intelligence and the Engineering Research center of Autonomous Unmanned System Technology Ministry of EducationAnhui UniversityHefei 230601China

Dear Editor,This letter examines the fixed-time stability of the Nash equilibrium(NE)in non-cooperative *** propose a consensus-based NE seeking algorithm for situations where players do not have perfect information and communicate via a topology *** proposed algorithm can achieve NE in a fixed time that does not depend on initial conditions and can be adjusted in advance.

关键词： Fixed seeking letter

Design of SiNridge-slot micro-ring resonator and generation of dual-comb based on orthogonally bicolor pumping

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Optoelectronics Letters 2024年

作者： Wen Jin Wang Qian Yu Huimin Wu Zhengwei Zhang Hui School of Science， Xi'an Shiyou University Shaanxi Engineering Research center of Oil and Gas Resource Optical Fiber Detection Shaanxi Key Laboratory of measurement and Control Technology for Oil and Gas wells

A novel high quality-factor （Q） micro-ring resonator （MRR） structure based on the Si3N4ridge-slot waveguide is proposed， and the MRR is pumped by orthogonally polarized bicolor pumping to generate dual-comb. We optimized the structure of MRR by the finite element method and precise dispersion engineering， which finally obtained the suitable MRR geometry with negative dispersion characteristics at 1550 nm， having Q of 1.7×107and the absorption loss as low as 2.6×10-5dB/cm. The simulation model of generating dual-comb is established as coupled Lugiato-Lefever equation （LLE）， which takes into account the higher order dispersion， cross-phase modulation （XPM）， multiphoton absorption， and external pumping. Solved by the split-step Fourier method （SSFM） and the fourth-order Runge-Kutta （RK4） method， the numerical results show that the generated dual-comb is periodically equally spaced distribution but with slightly different intensities in the time domain. In the frequency domain， there are 64 comb teeth with intensities higher than -100 dBm with a bandwidth of 120 nm. Particularly， in the case of bicolor orthogonal polarization pumping， a smaller amount of detuning does not greatly affect the bandwidth of the dual-comb.

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Interlayer Magnetic Interaction in the CrI_(3)/CrSe_(2) Heterostructure

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Chinese Physics Letters 2024年第5期41卷 85-89页

作者：王秋皓倪美燕李淑静郑法伟路洪艳张平 School of Physics and Physical Engineering Qufu Normal UniversityQufu 273165China center for Quantum Physics Key Laboratory of Advanced Optoelectronic Quantum Architecture and MeasurementSchool of PhysicsBeijing Institute of TechnologyBeijing 100081China Beijing Key Lab of Nanophotonics and Ultrafine Optoelectronic Systems School of PhysicsBeijing Institute of TechnologyBeijing 100081China College of Mathematics and Physics Beijing University of Chemical TechnologyBeijing 100029China Institute of Applied Physics and Computational Mathematics Beijing 100088China

Based on first-principles calculations, we systematically study the stacking energy and interlayer magnetic interaction of the heterobilayer composed of CrI_(3) and CrSe_(2) monolayers. It is found that the stacking order plays a crucial role in the interlayer magnetic coupling. Among all possible stacking structures, the AA-stacking is the most stable heterostructure, exhibiting interlayer antiferromagnetic interactions. Interestingly, the interlayer magnetic interaction can be effectively tuned by biaxial strain. A 4.3% compressive strain would result in a ferromagnetic interlayer interaction in all stacking orders. These results reveal the magnetic properties of CrI_(3)/CrSe_(2) heterostructure, which is expected to be applied to spintronic devices.

关键词： strain stacking interlayer

Design of Si3N4 ridge-slot micro-ring resonator and generation of dual-comb based on orthogonally bicolor pumping

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Optoelectronics Letters 2024年第11期 647-653页

作者： WEN Jin WANG Qian YU Huimin WU Zhengwei ZHANG Hui School of Science Xi'an Shiyou University Shaanxi Engineering Research center of Oil and Gas Resource Optical Fiber Detection Shaanxi Key Laboratory of measurement and Control Technology for Oil and Gas wells

A novel high quality-factor（Q） micro-ring resonator（MRR） structure based on the Si3N4ridge-slot waveguide is proposed, and the MRR is pumped by orthogonally polarized bicolor pumping to generate dual-comb.

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Ultra-compact wavelength multiplexer/demultiplexer based on subwavelength grating-assisted multimode interference coupler by inverse design

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Optoelectronics Letters 2024年

作者： WEN Jin PAN Yu WU Zhengwei ZHANG Ying School of Science， Xi'an Shiyou University Shaanxi Engineering Research center of Oil and Gas Resource Optical Fiber Detection Shaanxi Key Laboratory of measurement and Control Technology for Oil and Gas Wells

Inverse design of on-chip wavelength multiplexer/demultiplexer has attracted significant attention to improve equipment performance and miniaturization. We proposed and demonstrated the ultra-compact 1310/1550 nm wavelength multiplexer/demultiplexer assisted by subwavelength grating （SWG） using particle swarm optimization （PSO） algorithm in silicon-on-insulator （SOI） platform. Through the self-imaging effect of multimode interference （MMI） coupler， the demultiplexing function for 1310 nm and 1550 nm wavelengths is implemented. After that， three parallel SWG-based slots are inserted into the MMI section so that the effective refractive index of the modes can be engineered and thus the beat length can be adjusted. Importantly， these three SWG slots significantly reduce the length of the device， which is much shorter than the length of traditional MMI-based wavelength demultiplexers. Ultimately， by using the PSO algorithm， the equivalent refractive index and width of the SWG in a certain range are optimized to achieve the best performance of the wavelength demultiplexer. It has been verified that the device footprint is only 2×30.68 μm2， and 1dB bandwidths of larger than 120 nm are acquired at 1310 nm and 1550 nm wavelengths. Meanwhile， the transmitted spectrum shows that the insertion loss （IL） values are below 0.47 dB at both wavelengths when the extinction ratios （ER） values are above 12.65 dB. This inverse design approach has been proved to be efficient in increasing bandwidth and reducing device length.

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Probing signals of atmospheric gravity waves excited by the July 29,2021 M_(W)8.2 Alaska earthquake

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Geodesy and Geodynamics 2024年第3期15卷 219-229页

作者： Geng Zhang Jianqiao Xu Xiaodong Chen Heping Sun Lizhuo Gong State Key Laboratory of Geodesy and Earth's Dynamics Innovation Academy for Precision Measurement Science and TechnologyChinese Academy of SciencesWuhan430077China University of Chinese Academy of Sciences Beijing100049China

It is commonly believed that the atmosphere is decoupled from the solid ***,it is difficult for the seismic wave energy inside the Earth to propagate into the atmosphere,and atmospheric pressure wave signals excited by earthquakes are unlikely to exist in atmospheric *** increasing number of studies have shown that earthquakes,volcanoes,and tsunamis can perturb the Earth's atmosphere due to various coupling ***,the observations mainly focus on acoustic waves with periods of less than 10 min and inertial gravity waves with periods of greater than 1 *** are almost no clear observations of gravity waves that coincide with observations of low-frequency signals of the Earth's free oscillation frequency band within 1 *** paper investigates atmospheric gravity wave signals within1 h of surface-atmosphere observations using the periodogram method based on seismometer and microbarometer observations from the global seismic network before and after the July 29,2021 M_(w)8.2 Alaska earthquake in the United *** numerical results show that the atmospheric gravity wave signals with frequencies similar to those of the Earth's free oscillations _(0)S_(2) and _(0)T_(2) can be detected in the microbaro meter *** results con firm the existence of atmospheric gravity waves,indicating that the atmosphere and the solid Earth are not decoupled within this frequency band and that seismic wave energy excited by earthquakes can propagate from the interior of the Earth to the atmosphere and enhance the atmospheric gravity wave signals within 1 h.

关键词： Atmospheric gravity modes Atmospheric gravity waves Alaska earthquake Normal modes Coupling of solid earth and atmosphere

Regulating^(*)COOH intermediate via amino alkylation engineering for exceptionally effective photocatalytic CO_(2) reduction

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Journal of Energy Chemistry 2024年第5期92卷 282-291页

作者： Chengcheng Chen Qiaoyu Zhang Fangting Liu Zhengguo Zhang Qiong Liu Xiaoming Fang Key Laboratory of Enhanced Heat Transfer and Energy Conservation The Ministry of EducationSchool of Chemistry and Chemical EngineeringSouth China University of TechnologyGuangzhou 510640GuangdongChina Guangdong Provincial Key Laboratory of Chemical measurement and Emergency Test Technology(China) Institute of AnalysisGuangdong Academy of Sciences(China National Analytical CenterGuangzhou)Guangzhou 510070GuangdongChina Guangdong Engineering Technology Research center of Efficient Heat Storage and Application South China University of TechnologyGuangzhou 510640GuangdongChina Guangdong Provincial Key Laboratory of Fuel Cell Technology South China University of TechnologyGuangzhou 510640GuangdongChina

Photocatalytic reduction of CO_(2) into fuel represents a promising approach for achieving carbon neutrality,while realizing high selectivity in this process is challenging due to uncontrollable reaction intermediate and retarded desorption of target *** the interface microenvironment of catalysts has been proposed as a strategy to exert a significant influence on reaction outcomes,yet it remains a significant *** this study,amino alkylation was successfully integrated into the melem unit of polymeric carbon nitrides(PCN),which could efficiently drive the photocatalytic CO_(2) *** characterization and theoretical calculations revealed that the introduction of amino alkylation lowers the energy barrier for CO_(2) reduction into^(*)COOH intermediate,transforming the adsorption of^(*)COOH intermediate from the endothermic to an exothermic ***,the as-prepared materials demonstrated outstanding performance in photocatalytic CO_(2) reduction,yielding CO_(2)at a rate of 152.8μmol h^(-1) with a high selectivity of 95.4%and a quantum efficiency of 6.6%.

关键词： Polymeric carbonnitride Regulate intermediate Photocatalytic CO_(2)reduction Amino alkylation ^(*)COOH adsorption