This study introduces an innovative dual-tunable absorption film with the capability to switch between ultra-wideband and narrowband absorption.By manipulating the temperature,the film can achieve multi-band absorptio...This study introduces an innovative dual-tunable absorption film with the capability to switch between ultra-wideband and narrowband absorption.By manipulating the temperature,the film can achieve multi-band absorption within the 30-45 THz range or ultra-wideband absorption spanning 30-130 THz,with an absorption rate exceeding 0.9.Furthermore,the structural parameters of the absorption film are optimized using the particle swarm optimization(PSO)algorithm to ensure the optimal absorption response.The absorption response of the film is primarily attributed to the coupling of guided-mode resonance and local surface plasmon resonance effects.The film's symmetric structure enables polarization incoherence and allows for tuning through various means such as doping/voltage,temperature and structural parameters.In the case of a multi-band absorption response,the film exhibits good sensitivity to refractive index changes in multiple absorption modes.Additionally,the absorption spectrum of the film remains effective even at large incidence angles,making it highly promising for applications in fields such as biosensing and infrared stealth.展开更多
We design a four-band terahertz metamaterial absorber that relied on the block Dirac semi-metal(BDS).It is composed of a Dirac material layer,a gold reflecting layer,and a photonic crystal slab(PCS)medium layer.This s...We design a four-band terahertz metamaterial absorber that relied on the block Dirac semi-metal(BDS).It is composed of a Dirac material layer,a gold reflecting layer,and a photonic crystal slab(PCS)medium layer.This structure achieved perfect absorption of over 97%at 4.06 THz,6.15 THz,and 8.16 THz.The high absorption can be explained by the localized surface plasmon resonance(LSPR).And this conclusion can be proved by the detailed design of the surface structure.Moreover,the resonant frequency of the device can be dynamically tuned by changing the Fermi energy of the BDS.Due to the advantages such as high absorption,adjustable resonance,and anti-interference of incident angle and polarization mode,the Dirac semi-metal perfect absorber(DSPA)has great potential value in fields such as biochemical sensing,information communication,and nondestructive detection.展开更多
In order to significantly improve the absorption efficiency of monolayer molybdenum disulfide(M-MoS_(2)), an ultranarrowband M-MoS_(2)metamaterial absorber was obtained through theoretical analysis and numerical calcu...In order to significantly improve the absorption efficiency of monolayer molybdenum disulfide(M-MoS_(2)), an ultranarrowband M-MoS_(2)metamaterial absorber was obtained through theoretical analysis and numerical calculation using the finite difference time domain method. The physical mechanism can be better analyzed through critical coupling and guided mode resonance. Its absorption rate at λ = 806.41 nm is as high as 99.8%, which is more than 12 times that of bare MMoS_(2). From the simulation results, adjusting the geometric parameters of the structure can control the resonant wavelength range of the M-MoS_(2). In addition, we also found that the maximum quality factor is 1256.8. The numerical result shows that the design provides new possibilities for ultra-narrowband M-MoS_(2) perfect absorbers in the near-infrared spectrum.The results of this work indicate that the designed structure has excellent prospects for application in wavelength-selective photoluminescence and photodetection.展开更多
Optical skyrmions,as quasiparticles with non-trivial topological structures,have garnered significant attention in recent years.This paper proposes a method for customized spin angular momentum(SAM)distribution in hig...Optical skyrmions,as quasiparticles with non-trivial topological structures,have garnered significant attention in recent years.This paper proposes a method for customized spin angular momentum(SAM)distribution in highly localized focal fields,thereby enabling the generation of SAM skyrmion and bimeron topologies.The skyrmionic SAM textures can be flexibly controlled,such as polarity,vorticity,and helicity.In addition,the two-dimensional projection plane can be arbitrarily oriented within three-dimensional space.By utilizing time-reversal techniques,we obtain the required illumination fields of the 4π-focusing system and subsequently evaluate the tightly focused field using vector Debye integral theory.Our results show that the SAM orientation within the focal field is controlled by the orientation of orthogonal dipole pairs.Using the radiation field of a multi-concentric array of orthogonal dipole pairs,the distribution of SAM orientation in the target plane can be tailored to generate SAM topological structures such as skyrmions and bimerons.Highly localized and tunable SAM engineering holds great potential for applications in optical manipulation,light–matter interactions,optical information processing,transmission,and storage.展开更多
A quasi-Bessel beam(QBB)is suitable for laser ablation because it possesses a micrometer-sized focal spot and long depth of focus simultaneously.In this paper,the characterizations of QBBs formed by the ideal axicon a...A quasi-Bessel beam(QBB)is suitable for laser ablation because it possesses a micrometer-sized focal spot and long depth of focus simultaneously.In this paper,the characterizations of QBBs formed by the ideal axicon and oblate-tip axicon are described.Strong on-axis intensity oscillations occur due to interference between the QBB and the refracted beam by the oblate tip.Using the axicon for laser ablation was theoretically investigated.Simple analytical formulas can be used to predict the required laser parameters,including the laser pulse energy,the generated fluence distributions,and the beam diameters.展开更多
基金support by the National Natural Science Foundation of China(Nos.51606158,11604311,12074151)funding from the Sichuan Science and Technology Program(No.2021JDRC0022)+3 种基金funding from the Natural Science Foundation of Fujian Province(No.2021J05202)funding from the Research Project of Fashu Foundation(No.MFK23006)funding from the Open Fund of the Key Laboratory for Metallurgical Equipment and Control Technology of Ministry of Education in Wuhan University of Science and Technology,China(No.MECOF2022B01)funding by the project supported by Guangxi Key Laboratory of Precision Navigation Technology and Application,Guilin University of Electronic Technology(No.DH202321).
文摘This study introduces an innovative dual-tunable absorption film with the capability to switch between ultra-wideband and narrowband absorption.By manipulating the temperature,the film can achieve multi-band absorption within the 30-45 THz range or ultra-wideband absorption spanning 30-130 THz,with an absorption rate exceeding 0.9.Furthermore,the structural parameters of the absorption film are optimized using the particle swarm optimization(PSO)algorithm to ensure the optimal absorption response.The absorption response of the film is primarily attributed to the coupling of guided-mode resonance and local surface plasmon resonance effects.The film's symmetric structure enables polarization incoherence and allows for tuning through various means such as doping/voltage,temperature and structural parameters.In the case of a multi-band absorption response,the film exhibits good sensitivity to refractive index changes in multiple absorption modes.Additionally,the absorption spectrum of the film remains effective even at large incidence angles,making it highly promising for applications in fields such as biosensing and infrared stealth.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11604311,61705204,and 21506257)the Scientific Research Fund from Sichuan Provincial Science and Technology Department(Grant Nos.2020YJ0137 and 2020YFG0467)+2 种基金the Undergraduate Innovation Fund by Southwest University of Science and Technology(Grant No.JZ20-027)the Fund by the School of Science of Southwest University of Science and Technology for the Innovation Fund Project(Grant No.LX2020010)the Undergraduate Innovation and Entrepreneurship Training Program of Southwest University of Science and Technology(Grant No.S202010619073).
文摘We design a four-band terahertz metamaterial absorber that relied on the block Dirac semi-metal(BDS).It is composed of a Dirac material layer,a gold reflecting layer,and a photonic crystal slab(PCS)medium layer.This structure achieved perfect absorption of over 97%at 4.06 THz,6.15 THz,and 8.16 THz.The high absorption can be explained by the localized surface plasmon resonance(LSPR).And this conclusion can be proved by the detailed design of the surface structure.Moreover,the resonant frequency of the device can be dynamically tuned by changing the Fermi energy of the BDS.Due to the advantages such as high absorption,adjustable resonance,and anti-interference of incident angle and polarization mode,the Dirac semi-metal perfect absorber(DSPA)has great potential value in fields such as biochemical sensing,information communication,and nondestructive detection.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 11604311, 61705204, and 21506257)the Scientific Research Fund of Si Chuan Provincial Science and Technology Department, China (Grant Nos. 2020YJ0137 and 2020YFG0467)+1 种基金the National Defense Science and Technology Innovation Special Zone Project of China (Grant No. 19-163-21-TS-001-067-01)the College Students’s Innovation and Entrepreneurship Training Program (Grant No. S202110619065)。
文摘In order to significantly improve the absorption efficiency of monolayer molybdenum disulfide(M-MoS_(2)), an ultranarrowband M-MoS_(2)metamaterial absorber was obtained through theoretical analysis and numerical calculation using the finite difference time domain method. The physical mechanism can be better analyzed through critical coupling and guided mode resonance. Its absorption rate at λ = 806.41 nm is as high as 99.8%, which is more than 12 times that of bare MMoS_(2). From the simulation results, adjusting the geometric parameters of the structure can control the resonant wavelength range of the M-MoS_(2). In addition, we also found that the maximum quality factor is 1256.8. The numerical result shows that the design provides new possibilities for ultra-narrowband M-MoS_(2) perfect absorbers in the near-infrared spectrum.The results of this work indicate that the designed structure has excellent prospects for application in wavelength-selective photoluminescence and photodetection.
基金National Natural Science Foundation of China(12434012,92050202,12274299)Natural Science Foundation of Fujian Province(2024J01789,2022J011102)+1 种基金Science and Technology Commission of Shanghai Municipality(22QA1406600)Quanzhou City Science and Technology Program(2024QZGZ7)。
文摘Optical skyrmions,as quasiparticles with non-trivial topological structures,have garnered significant attention in recent years.This paper proposes a method for customized spin angular momentum(SAM)distribution in highly localized focal fields,thereby enabling the generation of SAM skyrmion and bimeron topologies.The skyrmionic SAM textures can be flexibly controlled,such as polarity,vorticity,and helicity.In addition,the two-dimensional projection plane can be arbitrarily oriented within three-dimensional space.By utilizing time-reversal techniques,we obtain the required illumination fields of the 4π-focusing system and subsequently evaluate the tightly focused field using vector Debye integral theory.Our results show that the SAM orientation within the focal field is controlled by the orientation of orthogonal dipole pairs.Using the radiation field of a multi-concentric array of orthogonal dipole pairs,the distribution of SAM orientation in the target plane can be tailored to generate SAM topological structures such as skyrmions and bimerons.Highly localized and tunable SAM engineering holds great potential for applications in optical manipulation,light–matter interactions,optical information processing,transmission,and storage.
基金The authors thank the financial support from the National Natural Science Foundation of China(No.11272120).
文摘A quasi-Bessel beam(QBB)is suitable for laser ablation because it possesses a micrometer-sized focal spot and long depth of focus simultaneously.In this paper,the characterizations of QBBs formed by the ideal axicon and oblate-tip axicon are described.Strong on-axis intensity oscillations occur due to interference between the QBB and the refracted beam by the oblate tip.Using the axicon for laser ablation was theoretically investigated.Simple analytical formulas can be used to predict the required laser parameters,including the laser pulse energy,the generated fluence distributions,and the beam diameters.
