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Preparation,optical properties and energy transfer of SrLaAlO4:Dy3+,Eu3+

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Journal of Rare Earths 2024年第11期42卷 2058-2067页

作者： Wei Chen Heng Zhang Desheng Zhu school of Physic and optoelectronic engineering Yangtze University

A series of Dy3+/Eu3+single doped and co-doped SrLaAlO4phosphors was synthesized by the traditional high-temperature solid-state method,and their structure,morphology and optical properties were *** X-ray diffraction（XRD） shows a small amount of doping with Dy3+and Eu3+does not change the crystal structure of the matrix SrLaAlO4and the best synthesis temperature is 1450℃.The scanning electron microscopy（SEM） indicates the particle size directly ranges from 1 to 5μm roughly and the energy dispersive spectroscopy（EDS） patterns show that SrLaAlO4:Dy3+phosphor and SrLaAlO4:Dy3+,Eu3+phosphor were successfully ***4:Dy3+phosphor can be effectively excited by near-ultraviolet light,producing two strong emission lights at 483 nm（blue light） and 579 nm（yellow light）,presenting a cold white light;SrLaAlO4:Eu3+phosphor can be effectively excited by nearultraviolet light,producing red lights at 622 nm;the characteristic emission peaks of Dy3+and Eu3+can be shown simultaneously under the same excitation wavelength in SrLaAlO4:Dy3+, Eu3+*** changing the relative doping concentration ratio of Dy3+and Eu3+,the modulation of SrLaAlO4:Dy3+,Eu3+phosphor from cold white to warm white light can be *** addition,the study of the luminescent mechanism and lifetime shows that there is energy transfer between Dy3+and Eu3+in SrLaAlO4:Dy3+,Eu3+phosphor.

关键词： Energy transfer High-temperature solid-phase method Luminescence properties Rare earths SrLaAlO4: Dy3+, Eu3+ White phosphor

A continuous-wave Nd:YVO_(4)-KGW intracavity Raman laser with over 34% diode-to-Stokes optical efficiency

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High Power Laser Science and engineering 2024年第2期12卷 62-68页

作者： Quan Sheng Jingni Geng Tianchang Liu Shijie Fu Wei Shi Jianquan Yao Institute of Laser and optoelectronics School of Precision Instrument and Optoelectronics EngineeringTianjin UniversityTianjinChina Key Laboratory of optoelectronic Information Technology(Ministry of Education) Tianjin UniversityTianjinChina

We demonstrate a continuous-wave(CW)Nd:YVO_(4)-potassium gadolinium tungstate(KGW)intracavity Raman laser with a diode-to-Stokes optical efficiency of 34.2%.By optimizing the cavity arrangement and reducing the cavity losses,8.47 W Stokes output at 1177 nm was obtained under an incident 878.6 nm diode pump power of 24.8 *** influence of cavity losses on the power and efficiency of the CW Raman laser,as well as the potential for further optimization,was investigated based on the numerical *** observation of thermally-induced output rollover was well explained by the calculation of the thermal lensing and cavity stability,indicating that the end-face curvature played an important role when the end-face of the crystal was highly reflective coated to make the cavity.A 10.9 W Stokes output under 40.9 W incident pump was also demonstrated with a cavity arrangement less sensitive to the end-face curvature,which is the highest output power of CW intracavity Raman lasers reported.

关键词： continuous wave intracavity Raman laser KGW crystal thermal lens

A star identification algorithm for rolling shutter exposure based on Hough transform

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Chinese Journal of Aeronautics 2024年第6期37卷 319-330页

作者： Tao WANG Gangyi WANG Xinguo WEI Yongyong LI school of instrumentation and optoelectronic engineering Beihang UniversityBeijing 100191China

The star identification algorithm usually identifies stars by angular distance ***,under high dynamic conditions,the rolling shutter effect distorts the angular distances between the measured and true star positions,leading to plethoric false matches and requiring complex and time-consuming verification for star *** identification rate hinders the application of low-noise and cost-effective rolling shutter image *** this work,we first study a rolling shutter distortion model of angular distances between stars,and then propose a novel three-stage star identification algorithm to identify distorted star images captured by the rolling shutter star *** first stage uses a modified grid algorithm with adaptive error tolerance and an expanded pattern database to efficiently eliminate spurious *** second stage performs angular velocity estimation based on Hough transform to verify the matches that follow the same distortion *** third stage applies a rolling shutter error correction method for further *** the simulation and night sky image test demonstrate the effectiveness and efficiency of our algorithm under high dynamic *** accuracy of angular velocity estimation method by Hough transform is evaluated and the root mean square error is below 0.5(°)/*** algorithm achieves a 95.7% identification rate at an angular velocity of 10(°)/s,which is much higher than traditional algorithms.

关键词： Star trackers Star identification Rolling shutter Angular velocity estimation Hough transform

Low-frequency hybridized excess vibrations of two-dimensional glasses

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Chinese Physics B 2024年第5期33卷 550-555页

作者：付立存郑一鸣王利近 school of Physics and optoelectronic engineering Anhui UniversityHefei 230601China

One hallmark of glasses is the existence of excess vibrational modes at low frequenciesωbeyond Debye’s *** studies suggest that understanding low-frequency excess vibrations could help gain insight into the anomalous mechanical and thermodynamic properties of ***,there is still intensive debate as to the frequency dependence of the population of low-frequency excess *** particular,excess modes could hybridize with phonon-like modes and the density of hybridized excess modes has been reported to follow D_(exc)(ω)~ω^(2)in 2D glasses with an inverse power law ***,the universality of the quadratic scaling remains unknown,since recent work suggested that interaction potentials could influence the scaling of the vibrational ***,we extend the universality of the quadratic scaling for hybridized excess modes in 2D to glasses with potentials ranging from the purely repulsive soft-core interaction to the hard-core one with both repulsion and attraction as well as to glasses with significant differences in density or interparticle ***,we observe that the number of hybridized excess modes exhibits a decrease in glasses with higher density or steeper interparticle repulsion,which is accompanied by a suppression of the strength of the sound *** results indicate that the density bears some resemblance to the repulsive steepness of the interaction in influencing low-frequency properties.

关键词： density of states vibrational modes sound attenuation two-dimensional glasses

The breaking of spin symmetry in the single-particle resonances in deformed nuclei

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Nuclear Science and Techniques 2024年第3期35卷 237-245页

作者： Zhen-Yu Zheng Shou-Wan Chen Quan Liu school of Physics and optoelectronic engineering Anhui UniversityHefei 230601China

The exploration of spin symmetry (SS) in nuclear physics has been instrumental in identifying atomic nucleus *** this study,we solve the Dirac equation from the relativistic mean field (RMF) in complex momentum *** investigated SS and its breaking in single-particle resonant states within deformed nuclei,with a focus on the illustrative *** was the initial discovery of a resonant spin doublet in a deformed nucleus,with the expectation of the SS approaching the continuum *** increasing single-particle energy,the splitting of the resonant spin doublets widened *** escalating splitting implies diminishing adherence to the SS,indicating a departure from the expected behavior as the energy levels *** also analyzed the width of the resonant states,showing that lower orbital angular momentum resonances possess shorter decay times and that SS is preserved within broad resonant doublets,as opposed to narrow resonant *** the radial density of the upper components for the bound-state and resonant-state doublets,it becomes evident that while SS is well-preserved in the bound states,it deteriorates in the resonant *** impact of nuclear deformation (β_(2)) on SS was examined,demonstrating that an increase in β_(2) resulted in higher energy and width splitting in the resonant spin doublets,which is attributed to increased component ***,the sensitivity of spin doublets to various potential parameters such as surface diffuseness (a),radius (R),and depth (Σ0) is discussed,emphasizing the role of these parameters in *** study provides valuable insights into the behavior of spin doublets in deformed nuclei and their interplay with the nuclear structure,thereby advancing our understanding of SS in the resonance state.

关键词： Spin symmetry Resonant states Deformed nuclei Complex-momentum representation

Detecting the quantum phase transition from the perspective of quantum information in the Aubry–André model

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Chinese Physics B 2024年第7期33卷 171-176页

作者：韦庚彪叶柳王栋 school of Physics and optoelectronic engineering Anhui UniversityHefei 230601China

We investigate the effectiveness of entropic uncertainty, entanglement and steering in discerning quantum phase transitions(QPTs). Specifically, we observe significant fluctuations in entropic uncertainty as the driving parameter traverses the phase transition point. It is observed that the entropic uncertainty, entanglement and quantum steering, based on the electron distribution probability, can serve as indicators for detecting QPTs. Notably, we reveal an intriguing anticorrelation relationship between entropic uncertainty and entanglement in the Aubry–André model. Moreover, we explore the feasibility of detecting a QPT when the period parameter is a rational number. These observations open up new and efficient avenues for probing QPTs.

关键词： quantum phase transition entropic uncertainty quantum entanglement quantum steering

Synchronization and firing mode transition of two neurons in a bilateral auditory system driven by a high–low frequency signal

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Chinese Physics B 2024年第5期33卷 722-735页

作者： Charles Omotomide Apata 唐浥瑞周祎凡蒋龙裴启明 school of Physics and optoelectronic engineering Yangtze UniversityJingzhou 434023China

The FitzHugh–Nagumo neuron circuit integrates a piezoelectric ceramic to form a piezoelectric sensing neuron,which can capture external sound signals and simulate the auditory neuron *** piezoelectric sensing neurons are coupled by a parallel circuit consisting of a Josephson junction and a linear resistor,and a binaural auditory system is *** the non-singleness of external sound sources,the high–low frequency signal is used as the input signal to study the firing mode transition and synchronization of this *** is found that the angular frequency of the high–low frequency signal is a key factor in determining whether the dynamic behaviors of two coupled neurons are *** they are in synchronization at a specific angular frequency,the changes in physical parameters of the input signal and the coupling strength between them will not destroy their *** addition,the firing mode of two coupled auditory neurons in synchronization is affected by the characteristic parameters of the high–low frequency signal rather than the coupling *** asynchronous dynamic behavior and variations in firing modes will harm the auditory *** findings could help determine the causes of hearing loss and devise functional assistive devices for patients.

关键词： piezoelectric ceramic Josephson junction auditory neuron synchronization

Fabrication of Biomimetic Surface for Hydrophobic and Anti-icing Purposes via the Capillary Force Lithography

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Journal of Bionic engineering 2024年第1期21卷 74-83页

作者： Wenqiang Xing Yiping Tang Fengzhou Zhao Lichun Zhang Dengying Zhang school of Physics and optoelectronic engineering Ludong UniversityYantai 264025China

In this paper,inspired by lotus leaf surfaces,we fabricated biomimetic multi-scale micro-nano-structures by Two-Step Capillary Force Lithography(TS-CFL)and UV-assisted Capillary Force Lithography(UV-CFL).The experimental results indicated that TS-CFL was unfitted to fabricate large-area multi-scale ***,UV-CFL can fabricate large-area multi-scale *** discussed the hydrophobic and anti-icing properties of the biomimetic surfaces fabricated by these two *** found that small structures are significant for improving the hydrophobic anti-icing properties of single-structured or structureless *** believe that these results can complement the experimental details of both technologies and enable the development of more interesting micro-nano-structures biomimetic surfaces by both technologies in the future.

关键词： Capllary force lithography Biomimetic lotus leaf Multi-scale structures Hydrophobic Anti-icing

Detection of transient mode-locking dynamics for a femtosecond Yb:KGW laser

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Chinese Optics Letters 2024年第8期22卷 70-76页

作者： Huimin Liu Jinrong Tian Zexin Zhang Haiyan Liu Lin Mao Yanrong Song school of Physics and optoelectronic engineering Beijing University of TechnologyBeijing 100124China

The evolution dynamics of mode locking for a solid-state femtosecond Yb:KGW laser is demonstrated and detected with time-stretch dispersive Fourier transform(DFT)technique for the first time,to the best of our *** Yb:KGW laser is constructed first with a classical X-shaped cavity,and SESAM-assisted Kerr lens mode locking is ***,a DFT device is built to record the buildup and extinction dynamics of the mode-locked *** results suggest that the time of extinction is slightly shorter than the buildup time and both of them experience complex *** results indicate that DFT could also be suitable to detect the transient buildup and extinction process in solid-state lasers,which would help investigate both the evolution of mode locking and characteristics determination for solid-state lasers.

关键词： dynamic process dispersive Fourier transform mode-locked solid-state laser