Color filters in different surroundings inherently suffer from angular sensitivity,which hinders their practical applications.Here,we present an angle-insensitive plasmonic filter that can produce different color resp...Color filters in different surroundings inherently suffer from angular sensitivity,which hinders their practical applications.Here,we present an angle-insensitive plasmonic filter that can produce different color responses to different surrounding environments.The color filters are based on a two-dimensional periodically and randomly distributed silver nanodisk array on a silica substrate.The proposed plasmonic color filters not only produce bright colors by altering the diameter of the Ag nanodisk,but also achieve continuous color palettes by changing the surrounding environment.Due to the weak coupling between the metallic nanodisks,the plasmonic color filters can enable good incident angle-insensitive properties(up to 30°).The strategy presented here could exhibit robust and promising applicability in anti-counterfeiting and imaging technologies.展开更多
Low-noise terahertz(THz)radiation over 100 MV/cm generation by a linearly-polarized relativistic laser pulse interacting with a near-critical-density(NCD)plasma slab is studied by theory and particle-in-cell(PIC)simul...Low-noise terahertz(THz)radiation over 100 MV/cm generation by a linearly-polarized relativistic laser pulse interacting with a near-critical-density(NCD)plasma slab is studied by theory and particle-in-cell(PIC)simulations.A theoretical model is established to examine the dipole-like radiation emission.The THz radiation is attributed to the singlecycle low-frequency surface current,which is longitudinally constrained by the quasi-equilibrium established by the laser ponderomotive force and the ponderomotively induced electrostatic force.Through theoretical analysis,the spatiotemporal characteristics,polarization property of the THz radiation,and the relation between the radiation strength with the initial parameters of driving laser and plasma are obtained,which are in good consistence with the PIC simulation results.Furthermore,it is found by PIC simulations that the generation of thermal electrons can be suppressed within the appropriate parameter regime,resulting in a clear THz radiation waveform.The appropriate parameter region is given for generating a low-noise intense THz radiation with peak strength reaching 100 MV/cm,which could find potential applications in nonlinear THz physics.展开更多
基金Project supported by the National Key Research and Development Program of China(Grant No.2022YFB2804602)Shanghai Pujiang Program(Grant No.21PJD048).
文摘Color filters in different surroundings inherently suffer from angular sensitivity,which hinders their practical applications.Here,we present an angle-insensitive plasmonic filter that can produce different color responses to different surrounding environments.The color filters are based on a two-dimensional periodically and randomly distributed silver nanodisk array on a silica substrate.The proposed plasmonic color filters not only produce bright colors by altering the diameter of the Ag nanodisk,but also achieve continuous color palettes by changing the surrounding environment.Due to the weak coupling between the metallic nanodisks,the plasmonic color filters can enable good incident angle-insensitive properties(up to 30°).The strategy presented here could exhibit robust and promising applicability in anti-counterfeiting and imaging technologies.
基金the National Natural Science Foundation of China(Grant Nos.11774430,12075157,11775202,and 12175310)the Scientific Research Foundation of Hunan Provincial Education Department(Grant No.20A042).
文摘Low-noise terahertz(THz)radiation over 100 MV/cm generation by a linearly-polarized relativistic laser pulse interacting with a near-critical-density(NCD)plasma slab is studied by theory and particle-in-cell(PIC)simulations.A theoretical model is established to examine the dipole-like radiation emission.The THz radiation is attributed to the singlecycle low-frequency surface current,which is longitudinally constrained by the quasi-equilibrium established by the laser ponderomotive force and the ponderomotively induced electrostatic force.Through theoretical analysis,the spatiotemporal characteristics,polarization property of the THz radiation,and the relation between the radiation strength with the initial parameters of driving laser and plasma are obtained,which are in good consistence with the PIC simulation results.Furthermore,it is found by PIC simulations that the generation of thermal electrons can be suppressed within the appropriate parameter regime,resulting in a clear THz radiation waveform.The appropriate parameter region is given for generating a low-noise intense THz radiation with peak strength reaching 100 MV/cm,which could find potential applications in nonlinear THz physics.
