A one-dimensional silicon based photonic crystal with nonlinear defect layers is examined. The linear and nonlinear optical properties are analyzed. The transmission spectrum was obtained by applying the optical trans...A one-dimensional silicon based photonic crystal with nonlinear defect layers is examined. The linear and nonlinear optical properties are analyzed. The transmission spectrum was obtained by applying the optical transfer matrix formalism to the photonic crystal. The various transmittance peaks obtained with the defect layers are investigated. The nature of the transmittance peak is analyzed with the number of defect layers.展开更多
Periodic photonic structures can provide rich modulation in propagation of light due to well-defined band structures.Especially near band edges,light localization and the effect of near-zero refractive index have attr...Periodic photonic structures can provide rich modulation in propagation of light due to well-defined band structures.Especially near band edges,light localization and the effect of near-zero refractive index have attracted wide attention.However,the practically fabricated structures can only have finite size,i.e.,limited numbers of periods,leading to changes of the light propagation modulation compared with infinite structures.Here,we study the size effect on light localization and near-zero refractive-index propagation near band edges in one-dimensional periodic structures.Near edges of the band gap,as the structure's size shrinks,the broadening of the band gap and the weakening of the light localization are discovered.When the size is small,an added layer on the surface will perform large modulation in the group velocity.Near the degenerate point with Dirac-like dispersion,the zero-refractive-index effects like the zero-phase difference and near-unity transmittance retain as the size changes,while absolute group velocity fluctuates when the size shrinks.展开更多
The complex band structures of a 1D anisotropic graphene photonic crystal are investigated, and the dispersion relations are confirmed using the transfer matrix method and simulation of commercial software. It is foun...The complex band structures of a 1D anisotropic graphene photonic crystal are investigated, and the dispersion relations are confirmed using the transfer matrix method and simulation of commercial software. It is found that the result of using effective medium theory can fit the derived dispersion curves in the low wave vector.Transmission, absorption, and reflection at oblique incident angles are studied for the structure, respectively.Omni-gaps exist for angles as high as 80° for two polarizations. Physical mechanisms of the tunable dispersion and transmission are explained by the permittivity of graphene and the effective permittivity of the multilayerstructure.展开更多
Controlling the distribution of solar spectrum in different bands would boost the energy harvesting efficiency and optimize the energy dispatchability.1D photonic crystal with intrinsic optical band gap can be used to...Controlling the distribution of solar spectrum in different bands would boost the energy harvesting efficiency and optimize the energy dispatchability.1D photonic crystal with intrinsic optical band gap can be used to split the solar spectrum for hybrid photovoltaic/thermal solar applications.Here,we designed an efficient solar spectrum optical filter based on a cermet layer,Si/SiO_(2)1D photonic crystal,and top heterostructure layer.Compared with 1D photonic crystal structure,the 1D photonic crystal heterostructure with top YSZ layer can realize the reflectance of greater than 92%in PV band and the low average reflectance in two thermal bands by tuning the effective impedance of multilayer films.The enhanced reflectance in PV band results from the huge mismatching of impedance between free space and the heterostructure structure.The top dielectric layer can also be extended to other oxides.展开更多
A new type of optical fiber is presented here. It consists of a coaxial optical fiber, bounded by dielectric, multilayer and omnidirectional reflecting mirrors. Jones matrix method is used to analyze the influence of ...A new type of optical fiber is presented here. It consists of a coaxial optical fiber, bounded by dielectric, multilayer and omnidirectional reflecting mirrors. Jones matrix method is used to analyze the influence of the layer number of one Dimensional (1D) photonic crystals on their reflectivity. The numerical results show that this type of fiber can be used to guide light around sharp bends whose radius of curvature can be as small as the wavelength of light without significant scattering losses.展开更多
One dimensional(1D)nanostructures attract considerable attention,enabling a broad application owing to their unique properties.However,the precise mechanism of 1D morphology attainment remains a matter of debate.In th...One dimensional(1D)nanostructures attract considerable attention,enabling a broad application owing to their unique properties.However,the precise mechanism of 1D morphology attainment remains a matter of debate.In this study,ultrafast picosecond(ps)laser-induced treatment on upconversion nanoparticles(UCNPs)is offered as a tool for 1 D-nanostructures formation.Fragmentation,reshaping through recrystallization process and bioadaptation of initially hydrophobic(β-Na_(1.5)Y_(1.5_)F_(6):Yb^(3+),Tm^(3+)/β-Na_(1.5)Y_(1.5_)F_(6))core/shell nanoparticles by means of one-step laser treatment in water are demonstrated.“True”1D nanostructures through"Medusa^-like structures can be obtained,maintaining anti-Stokes luminescence functionalities.A matter of the one-dimensional UCNPs based on direction of energy migration processes is debated.The proposed laser treatment approach is suitable for fast UCNP surface modification and nano-to-nano transformation,that open unique opportunities to expand UCNP applications in industry and biomedicine.展开更多
文摘A one-dimensional silicon based photonic crystal with nonlinear defect layers is examined. The linear and nonlinear optical properties are analyzed. The transmission spectrum was obtained by applying the optical transfer matrix formalism to the photonic crystal. The various transmittance peaks obtained with the defect layers are investigated. The nature of the transmittance peak is analyzed with the number of defect layers.
基金the National Key Basic Research Program of China(Grant No.2022YFA1404800)the National Natural Science Foundation of China(Grant Nos.12234007 and 12221004)supported by Science and Technology Commission of Shanghai Municipality,China(Grant Nos.19XD1434600,2019SHZDZX01,19DZ2253000,20501110500,and 21DZ1101500)。
文摘Periodic photonic structures can provide rich modulation in propagation of light due to well-defined band structures.Especially near band edges,light localization and the effect of near-zero refractive index have attracted wide attention.However,the practically fabricated structures can only have finite size,i.e.,limited numbers of periods,leading to changes of the light propagation modulation compared with infinite structures.Here,we study the size effect on light localization and near-zero refractive-index propagation near band edges in one-dimensional periodic structures.Near edges of the band gap,as the structure's size shrinks,the broadening of the band gap and the weakening of the light localization are discovered.When the size is small,an added layer on the surface will perform large modulation in the group velocity.Near the degenerate point with Dirac-like dispersion,the zero-refractive-index effects like the zero-phase difference and near-unity transmittance retain as the size changes,while absolute group velocity fluctuates when the size shrinks.
基金National Natural Science Foundation of China(NSFC)(61107030)Fundamental Research Funds for the Central Universities of ChinaOpening Foundation of the State Key Laboratory of Millimeter Waves(K201703)
文摘The complex band structures of a 1D anisotropic graphene photonic crystal are investigated, and the dispersion relations are confirmed using the transfer matrix method and simulation of commercial software. It is found that the result of using effective medium theory can fit the derived dispersion curves in the low wave vector.Transmission, absorption, and reflection at oblique incident angles are studied for the structure, respectively.Omni-gaps exist for angles as high as 80° for two polarizations. Physical mechanisms of the tunable dispersion and transmission are explained by the permittivity of graphene and the effective permittivity of the multilayerstructure.
基金the National Natural Science Foundation of China(51871081,11674078 and 51971081)the Natural Science Foundation of Guangdong Province of China(2018A0303130033)+1 种基金Shenzhen Fundamental Research Project(JCYJ20170811155832192)Natural Scientific Research Innovation Foundation in Harbin Institute of Technology(HIT.NSRIF.2020060).
文摘Controlling the distribution of solar spectrum in different bands would boost the energy harvesting efficiency and optimize the energy dispatchability.1D photonic crystal with intrinsic optical band gap can be used to split the solar spectrum for hybrid photovoltaic/thermal solar applications.Here,we designed an efficient solar spectrum optical filter based on a cermet layer,Si/SiO_(2)1D photonic crystal,and top heterostructure layer.Compared with 1D photonic crystal structure,the 1D photonic crystal heterostructure with top YSZ layer can realize the reflectance of greater than 92%in PV band and the low average reflectance in two thermal bands by tuning the effective impedance of multilayer films.The enhanced reflectance in PV band results from the huge mismatching of impedance between free space and the heterostructure structure.The top dielectric layer can also be extended to other oxides.
文摘A new type of optical fiber is presented here. It consists of a coaxial optical fiber, bounded by dielectric, multilayer and omnidirectional reflecting mirrors. Jones matrix method is used to analyze the influence of the layer number of one Dimensional (1D) photonic crystals on their reflectivity. The numerical results show that this type of fiber can be used to guide light around sharp bends whose radius of curvature can be as small as the wavelength of light without significant scattering losses.
基金the Ministry of Science and Higher Education within the State assignment FSRC《Crystallography and Photonics》RAS in part of《UCNP synthesis》,by the Russian Foundation for Basic Research according to the research projects No 18-29-20064 in the part of《PL analysis》and Ns 20-32-70174 in the part o f《complex structures analysis》,by the Russian Science Foundation project No18-79-10198 in the part of《UCNP analysis》.BC acknowledges financial support from Lower Saxony through“Quanten und Nanometrologie”project(QUANOMET)and DFG Cluster of Excellence PhoenixD(EXC 2122,Project ID 390833453).
文摘One dimensional(1D)nanostructures attract considerable attention,enabling a broad application owing to their unique properties.However,the precise mechanism of 1D morphology attainment remains a matter of debate.In this study,ultrafast picosecond(ps)laser-induced treatment on upconversion nanoparticles(UCNPs)is offered as a tool for 1 D-nanostructures formation.Fragmentation,reshaping through recrystallization process and bioadaptation of initially hydrophobic(β-Na_(1.5)Y_(1.5_)F_(6):Yb^(3+),Tm^(3+)/β-Na_(1.5)Y_(1.5_)F_(6))core/shell nanoparticles by means of one-step laser treatment in water are demonstrated.“True”1D nanostructures through"Medusa^-like structures can be obtained,maintaining anti-Stokes luminescence functionalities.A matter of the one-dimensional UCNPs based on direction of energy migration processes is debated.The proposed laser treatment approach is suitable for fast UCNP surface modification and nano-to-nano transformation,that open unique opportunities to expand UCNP applications in industry and biomedicine.
