We demonstrate an effective and optimal strategy for generating spatially resolved longitudinal spin angular momentum(LSAM)in optical tweezers by tightly focusing the first-order spirally polarized vector(SPV)beams wi...We demonstrate an effective and optimal strategy for generating spatially resolved longitudinal spin angular momentum(LSAM)in optical tweezers by tightly focusing the first-order spirally polarized vector(SPV)beams with zero intrinsic angular momentum into a refractive index stratified medium.The stratified medium gives rise to a spherically aberrated intensity profile near the focal region of the optical tweezers,with off-axis intensity lobes in the radial direction possessing opposite LSAM(helicities corresponding toσ=+1 and−1)compared to the beam center.We trap mesoscopic birefringent particles in an off-axis intensity lobe as well as at the beam center by modifying the trapping plane and observe particles spinning in opposite directions depending on their location.The direction of rotation depends on the particle size with larger particles spinning either clockwise or anticlockwise depending on the direction of spirality of the polarization of the SPV beam after tight focusing,while smaller particles spin in both directions depending on their spatial locations.Numerical simulations support our experimental observations.Our results introduce new avenues in spin-orbit optomechanics to facilitate novel yet straightforward avenues for exotic and complex particle manipulation in optical tweezers.展开更多
Based on angular amplitude modulation of orthogonal base vectors in common-path interference method, we propose an interesting type of hybrid vector beams with unprecedented azimuthal polarization gradient and demonst...Based on angular amplitude modulation of orthogonal base vectors in common-path interference method, we propose an interesting type of hybrid vector beams with unprecedented azimuthal polarization gradient and demonstrate in experiment. Geometrically, the configured azimuthal polarization gradient is indicated by intriguing mapping tracks of angular polarization states on Poincaré sphere, more than just conventional circles for previously reported vector beams. Moreover, via tailoring relevant parameters, more special polarization mapping tracks can be handily achieved. More noteworthily, the designed azimuthal polarization gradients are found to be able to induce azimuthally non-uniform orbital angular momentum density, while generally uniform for circle-track cases, immersing in homogenous intensity background whatever base states are. These peculiar features may open alternative routes for new optical effects and applications.展开更多
Based on the extended Huygens-Fresnel principle, the propagation of cylindrical vector beams in a turbulent atmosphere is investigated. The intensity distribution and the polarization degree of beams on propagation ar...Based on the extended Huygens-Fresnel principle, the propagation of cylindrical vector beams in a turbulent atmosphere is investigated. The intensity distribution and the polarization degree of beams on propagation are studied. It is found that the beam profile has a Gaussian shape under the influence of the atmospheric turbulence, and the polarization distribution shows a dip in the cross section as the beam propagates in the turbulent atmosphere. It is also found that the beam profile and the polarization distribution are closely related to beam parameter and atmospheric turbulence.展开更多
Due to the large exciton binding energy,two-dimensional(2D)transition metal dichalcogenides(TMDCs)provide an ideal platform for studying excitonic states and related photonics and optoelectronics.Polarization states l...Due to the large exciton binding energy,two-dimensional(2D)transition metal dichalcogenides(TMDCs)provide an ideal platform for studying excitonic states and related photonics and optoelectronics.Polarization states lead to distinct light-matter interactions which are of great importance for device applications.In this work,we study polarized photoluminescence spectra from intralayer exciton and indirect exciton in WS_(2) and WSe_(2) atomic layers,and interlayer exciton in WS_(2)/WSe_(2) heterostructures by radially and azimuthally polarized cylindrical vector laser beams.We demonstrated the same in-plane and out-of-plane polarization behavior from the intralayer and indirect exciton.Moreover,with these two laser modes,we obtained interlayer exciton in WS_(2)/WSe_(2) heterostructures with stronger out-of-plane polarization,due to the formation of vertical electric dipole moment.展开更多
A cylindrical vector beam is utilized to enhance the energy scale of the pulse post-compressed in a bulk-material Herriott multi-pass cell(MPC).The method proposed here enables,for the first time to the best of our kn...A cylindrical vector beam is utilized to enhance the energy scale of the pulse post-compressed in a bulk-material Herriott multi-pass cell(MPC).The method proposed here enables,for the first time to the best of our knowledge,pulse compression from 14 ps down to 475 fs with throughput energy beyond 1 mJ,corresponding to a compression ratio of 30,which is the highest pulse energy and compression ratio in single-stage bulk-material MPCs.Furthermore,we demonstrate the characteristic of the vector polarization beam is preserved in the MPC.展开更多
Vector beams with spiral phase and spatially varying polarization profiles have many applications from optical micromanipulation to materials processing. Here, we propose and demonstrate an atomic spatial mode extract...Vector beams with spiral phase and spatially varying polarization profiles have many applications from optical micromanipulation to materials processing. Here, we propose and demonstrate an atomic spatial mode extracting scheme for the vector beam based on polarization-dependent absorption in the atom vapor. By employing the linear polarization pump beam which induces polarization sensitive absorption in the atomic ensemble, a counter-propagated weak probe vector beam is extracted by spatial absorption, and extracted part still maintains the original polarization and the vortex phase.The topological charges of the extracted mode are verified by interfering with the Gaussian beam, and it can be found that the orbital angular momentum is conserved in the extracting process. Our work will have potential applications in non-destructive spatial mode identification, and is also useful for studying higher-dimensional quantum information based on atomic ensembles.展开更多
We propose a method for generating double-ring-shaped vector beams. A step phase introduced by a spatial light modulator（SLM） first makes the incident laser beam have a nodal cycle. This phase is dynamic in nature b...We propose a method for generating double-ring-shaped vector beams. A step phase introduced by a spatial light modulator（SLM） first makes the incident laser beam have a nodal cycle. This phase is dynamic in nature because it depends on the optical length. Then a Pancharatnam–Berry phase（PBP） optical element is used to manipulate the local polarization of the optical field by modulating the geometric phase. The experimental results show that this scheme can effectively create double-ring-shaped vector beams. It provides much greater flexibility to manipulate the phase and polarization by simultaneously modulating the dynamic and the geometric phases.展开更多
We propose a simple and efficient method that uses a single focused hybrid vector beam to confine metallic Rayleigh particles at multiple positions.We study the force mechanisms of multiple trapping by analyzing the g...We propose a simple and efficient method that uses a single focused hybrid vector beam to confine metallic Rayleigh particles at multiple positions.We study the force mechanisms of multiple trapping by analyzing the gradient and scattering forces.It is observed that the wavelength and topological charges of the hybrid vector beam regulate the trapping positions and number of optical trap sites.The proposed method can be implemented easily in three-dimensional space, and it facilitates both trapping and organization of particles.Thus, it can provide an effective and controllable means for nanoparticle manipulation.展开更多
Polarization detection is essential for various applications,ranging from biological diagnostics to quantum optics.Although various metasurface-based polarimeters have emerged,these platforms are commonly realized thr...Polarization detection is essential for various applications,ranging from biological diagnostics to quantum optics.Although various metasurface-based polarimeters have emerged,these platforms are commonly realized through spatial-division designs,which restrict detection accuracy due to inherent factors such as crosstalk.Here,we propose,to our knowledge,a novel strategy for high-accuracy,broadband full-Stokes polarization detection based on the analysis of a single vector beam,whose polarization profile varies sensitively and exhibits a one-to-one correspondence with the incident polarization.Based on this,the incident polarization is completely encoded into the field profile of the vector beam,which avoids crosstalk in principle,and results in high-accuracy polarization detection without any calibration process.As a proof of concept,a geometric-phase metasurface-based grafted perfect vector vortex beam(GPVVB)generator was designed and fabricated.Experimental results demonstrate that our method achieves polarization detection with an average relative error of 2.25%.Benefiting from the broadband high transmittance exceeding 95%of the metasurface due to the femtosecond laser-induced birefringence process,our method operates across a wavelength range of 450–1100 nm.Furthermore,the detection capability of the vector beam polarization profile was validated using a GPVVB-generating array.These results highlight the potential of our approach for transformative applications in polarization detection,including optical communication and machine vision.展开更多
Broadband polarization measurement plays a crucial role in numerous fields,spanning from fundamental physics to a wide range of practical applications.However,traditional approaches typically rely on combinations of v...Broadband polarization measurement plays a crucial role in numerous fields,spanning from fundamental physics to a wide range of practical applications.However,traditional approaches typically rely on combinations of various dispersive optical elements,requiring bulky systems and complicated time-consuming multiple procedures.Here we have achieved broadband spectropolarimetry based on single-shot images for spatial intensity distributions of polychromatic vector beams.A custom-designed diffractive optical element and a vortex retarder convert the incident polychromatic waves into structured vector beams:the former diffracts light of different wavelengths into concentric circles of different radii,while the latter codes their polarization information into intensity distributions along the azimuthal direction.The validation experiments verify our exceptional measurement accuracy(RMS errors<1%)for each Stokes component in the visible light range(400-700 nm),with good spectral(<0.8 nm)and temporal(an output rate of 100 Hz)resolutions.We have further employed our broadband polarimeter to study the mutarotation of glucose,making direct observations of temporal evolutions of chemical reactions accessible.Our work has significantly broadened the toolboxes of spectropolarimetry,which can potentially incubate various disruptive applications that depend on broadband polarization measurements.展开更多
On-chip devices for generating pre-designed vectorial optical fields(VOFs)under surface wave(SW)excitations are highly desired in integrated photonics.However,conventional devices are usually of large footprints,low e...On-chip devices for generating pre-designed vectorial optical fields(VOFs)under surface wave(SW)excitations are highly desired in integrated photonics.However,conventional devices are usually of large footprints,low efficiencies,and limited wave-control capabilities.Here,we present a generic approach to design ultra-compact on-chip devices that can efficiently generate pre-designed VOFs under SW excitations,and experimentally verify the concept in terahertz(THz)regime.We first describe how to design SW-excitation metasurfaces for generating circularly polarized complex beams,and experimentally demonstrate two meta-devices to realize directional emission and focusing of THz waves with oppo-site circular polarizations,respectively.We then establish a systematic approach to construct an integrated device via merging two carefully designed metasurfaces,which,under SW excitations,can separately produce pre-designed far-field patterns with different circular polarizations and generate target VOF based on their interference.As a proof of con-cept,we demonstrate experimentally a meta-device that can generate a radially polarized Bessel beam under SW excita-tion at~0.4 THz.Experimental results agree well with full-wave simulations,collectively verifying the performance of our device.Our study paves the road to realizing highly integrated on-chip functional THz devices,which may find many ap-plications in biological sensing,communications,displays,image multiplexing,and beyond.展开更多
Cylindrical vector beams(CVBs),characterized by their spatially varying polarization and axial symmetry,have emerged as powerful tools for engineering light–matter interactions at the nanoscale.Unlike conventional li...Cylindrical vector beams(CVBs),characterized by their spatially varying polarization and axial symmetry,have emerged as powerful tools for engineering light–matter interactions at the nanoscale.Unlike conventional linearly polarized beams,tightly focused CVBs can generate strong longitudinal electric or magnetic field components,enabling the selective excitation of specific multipolar modes and various resulting modes in optical nanostructures.This unique field configuration facilitates the excitation of various optical phenomena such as anapole states,dark modes,Fano resonances,optical magnetism,and enhanced nonlinear optical responses,which are challenging to achieve with traditional illumination.We summarize recent advancements in nanophotonic phenomena/effects driven by CVB excitation,illustrated through seminal studies in plasmonic,dielectric,or hybrid nanostructures,offering promising opportunities for applications in imaging,sensing,optical trapping,quantum information processing,etc.We discuss how enhanced electromagnetic field confinement,increased coupling efficiency,and precise control over resonant scattering can lead to advanced nanophotonic phenomena/effects under CVB illumination.The insights presented here aim to guide future developments in structured light–matter interaction and inspire the design of advanced nanophotonic systems.展开更多
Perfect vortices,recognized for their distinct ring profile that remains independent of the topological charge,present significant challenges in generation due to the precise control needed over both phase and polariz...Perfect vortices,recognized for their distinct ring profile that remains independent of the topological charge,present significant challenges in generation due to the precise control needed over both phase and polarization.In this work,we introduce and validate a new approach for generating these beams,allowing the selection of diffferent azimuthally-variant phase gradients and vector states,thereby enabling full control over the phase and polarization patterns of perfect vortices.Using dual-functional silicon metaoptics,we achieve the compact generation of a novel class of perfect vortices,termed azimuthally-variant perfect vector beams.The optical characterization of the generated beams,performed through a filtering method,confirms their intrinsic azimuthally-variant vectorial nature.These beams exhibit unique properties that promise valuable applications in optical tweezing,the manipulation of low-refractive-index particles,the trapping of cold atoms,and high-capacity communications.展开更多
We propose a method for generating an all-fiber cylindrical vector beam(CVB)using a fiber Bragg grating(FBG)inscribed in a ring core fiber(RCF).The FBGs are inscribed using the femtosecond laser phase mask scanning te...We propose a method for generating an all-fiber cylindrical vector beam(CVB)using a fiber Bragg grating(FBG)inscribed in a ring core fiber(RCF).The FBGs are inscribed using the femtosecond laser phase mask scanning technique,chosen for its large ring core diameter and low photosensitivity of the RCF.Additionally,a lateral offset splicing spot is introduced to couple the fundamental mode to the second-order modes.Switchable LP_(01)and LP_(11)mode lasers can be achieved.Meanwhile,azimuthally and radially polarized CVBs are successfully realized by adjusting the polarization controllers.展开更多
The Bessel-like vector vortex beam(BlVVB)has gained increasing significance across numerous applications.However,its practical application is restricted by manufacturing difficulties and polarization manipulation.Thus...The Bessel-like vector vortex beam(BlVVB)has gained increasing significance across numerous applications.However,its practical application is restricted by manufacturing difficulties and polarization manipulation.Thus,the ability to manipulate its degrees of freedom is highly desirable.In this paper,the full-domain polarization modulation of BlVVB within a hot atomic ensemble has been investigated.We begin with the theoretical analysis of the resonant magneto-optical effect of atoms with a horizontal linear-polarized beam and experimentally demonstrate precise manipulation of the polarization state across the entire domain of the BlVVB,achieving an error margin of less than 3°at various cross-sectional points.Our study provides a novel approach for the modulation of BlVVB based on atomic media,which holds potential applications in sensitive vector magnetometers,optical communications,and signal processing.展开更多
The possibility to achieve unprecedented multiplexing of light-matter interaction in nanoscale is of virtue importance from both fundamental science and practical application points of view. Cylindrical vector beams(C...The possibility to achieve unprecedented multiplexing of light-matter interaction in nanoscale is of virtue importance from both fundamental science and practical application points of view. Cylindrical vector beams(CVBs) manifested as polarization vortices represent a robust and emerging degree of freedom for information multiplexing with increased capacities. Here, we propose and demonstrate massivelyencoded optical data storage(ODS) by harnessing spatially variant electric fields mediated by segmented CVBs. By tight focusing polychromatic segmented CVBs to plasmonic nanoparticle aggregates, recordhigh multiplexing channels of ODS through different combinations of polarization states and wavelengths have been experimentally demonstrated with a low error rate. Our result not only casts new perceptions for tailoring light-matter interactions utilizing structured light but also enables a new prospective for ultra-high capacity optical memory with minimalist system complexity by combining CVB’s compatibility with fiber optics.展开更多
This paper reports the experimental realization of efficiently sorting vector beams by polarization topological charge （PTC）. The PTC of a vector beam can be defined as the repetition number of polarization state ch...This paper reports the experimental realization of efficiently sorting vector beams by polarization topological charge （PTC）. The PTC of a vector beam can be defined as the repetition number of polarization state change along the azimuthal axis, while its sign stands for the rotating direction of the polarization. Here, a couple of liquid crystal Pancharatnam-Berry optical dements （PBOEs） have been used to introduce conjugated spatial phase modulations for two orthogonal circular polarization states. Applying these PBOEs in a 4-foptical system, our experiments show the setup can work for PTC sorting with a separation efficiency of more than 58%. This work provides an effective way to decode information from different PTCs, which may be interesting in many fields, especially in optical communication.展开更多
We reporte and demonstrate a solid-state laser to achieve controlled generation of order-switchable cylindrical vector beams(CVBs).In the cavity,a group of vortex wave plates(VWPs)with two quarter-wave plates between ...We reporte and demonstrate a solid-state laser to achieve controlled generation of order-switchable cylindrical vector beams(CVBs).In the cavity,a group of vortex wave plates(VWPs)with two quarter-wave plates between the VWPs was utilized to achieve mode conversion and order-switch of CVBs.By utilizing two VWPs of first and third orders,the second and fourth order CVBs were obtained,with mode purities of 96.8%and 94.8%,and sloping efficiencies of 4.45%and 3.06%,respectively.Furthermore,by applying three VWPs of first,second,and third orders,the mode-switchable Gaussian beam,second,fourth,and sixth order CVBs were generated.展开更多
A rotating neodymium-doped yttrium aluminum garnet(Nd:YAG)disk laser resonator for efficiently generating vector beams with azimuthal and radial polarization is demonstrated.In the study,the laser crystal rotary for t...A rotating neodymium-doped yttrium aluminum garnet(Nd:YAG)disk laser resonator for efficiently generating vector beams with azimuthal and radial polarization is demonstrated.In the study,the laser crystal rotary for thermal alleviation and polarization discrimination uses c-cut ytterbium vanadate(YVO_(4)).The laser output could be switched between azimuthal and radial polarizations by simply adjusting the cavity length.The laser power reached 4.38 W and 4.64W for azimuthally and radially polarized beams at the slope efficiencies of 45.3%and 48.5%,respectively.Our study proved that an efficient,high-power vector rotary disk laser would be realistic.展开更多
Noble metallic nanostructures with strong electric near-field enhancement can significantly improve nanoscale light-matter interactions and are critical for high-sensitivity surface-enhanced Raman spectroscopy[SERS].H...Noble metallic nanostructures with strong electric near-field enhancement can significantly improve nanoscale light-matter interactions and are critical for high-sensitivity surface-enhanced Raman spectroscopy[SERS].Here,we use an azimuthal vector beam[AVB]to illuminate the plasmonic tips circular cluster[PTCC]array to enhance the electric near-field intensity of the PTCC array,and then use it to improve SERS sensitivity.The PTCC array was prepared based on the self-assembled and inductive coupled plasmon[ICP]etching methods.The calculation results show that,compared with the linearly polarized beam[LPB]and radial vector beam excitations,the AVB excitation can obtain stronger electric near-field enhancement due to the strong resonant responses formed in the nanogap between adjacent plasmonic tips.Subsequently,our experimental results proved that AVB excitation increased SERS sensitivity to 10-13mol/L,which is two orders of magnitude higher than that of LPB excitation.Meanwhile,the PTCC array had excellent uniformity with the Raman enhancement factor calculated to be~2.4×10^[8].This kind of vector light field enhancing Raman spectroscopy may be applied in the field of sensing technologies,such as the trace amount detection.展开更多
基金the SERB,Department of Science and Technology,Government of India(Project No.EMR/2017/001456)aIISER Kolkata IPh.D fellowship for research.
文摘We demonstrate an effective and optimal strategy for generating spatially resolved longitudinal spin angular momentum(LSAM)in optical tweezers by tightly focusing the first-order spirally polarized vector(SPV)beams with zero intrinsic angular momentum into a refractive index stratified medium.The stratified medium gives rise to a spherically aberrated intensity profile near the focal region of the optical tweezers,with off-axis intensity lobes in the radial direction possessing opposite LSAM(helicities corresponding toσ=+1 and−1)compared to the beam center.We trap mesoscopic birefringent particles in an off-axis intensity lobe as well as at the beam center by modifying the trapping plane and observe particles spinning in opposite directions depending on their location.The direction of rotation depends on the particle size with larger particles spinning either clockwise or anticlockwise depending on the direction of spirality of the polarization of the SPV beam after tight focusing,while smaller particles spin in both directions depending on their spatial locations.Numerical simulations support our experimental observations.Our results introduce new avenues in spin-orbit optomechanics to facilitate novel yet straightforward avenues for exotic and complex particle manipulation in optical tweezers.
基金Project supported by the National Key Research and Development Program of China(Grant No.2017YFA0303800)the National Natural Science Foundation of China(Grant Nos.11634010,61675168,91850118,11774289,and 11804277)+1 种基金the Fundamental Research Funds for the Central Universities,China(Grant No.3102019JC008)the Basic Research Plan of Natural Science in Shaanxi Province,China(Grant Nos.2018JM1057 and 2019JM-583).
文摘Based on angular amplitude modulation of orthogonal base vectors in common-path interference method, we propose an interesting type of hybrid vector beams with unprecedented azimuthal polarization gradient and demonstrate in experiment. Geometrically, the configured azimuthal polarization gradient is indicated by intriguing mapping tracks of angular polarization states on Poincaré sphere, more than just conventional circles for previously reported vector beams. Moreover, via tailoring relevant parameters, more special polarization mapping tracks can be handily achieved. More noteworthily, the designed azimuthal polarization gradients are found to be able to induce azimuthally non-uniform orbital angular momentum density, while generally uniform for circle-track cases, immersing in homogenous intensity background whatever base states are. These peculiar features may open alternative routes for new optical effects and applications.
基金Project supported by the National Natural Science Foundation of China(Grant No.60977068)the Key Project of Science and Technology of Fujian Province,China(Grant No.2007H0027)the Natural Science Foundation of Fujian Province,China (Grant No.A0810012)
文摘Based on the extended Huygens-Fresnel principle, the propagation of cylindrical vector beams in a turbulent atmosphere is investigated. The intensity distribution and the polarization degree of beams on propagation are studied. It is found that the beam profile has a Gaussian shape under the influence of the atmospheric turbulence, and the polarization distribution shows a dip in the cross section as the beam propagates in the turbulent atmosphere. It is also found that the beam profile and the polarization distribution are closely related to beam parameter and atmospheric turbulence.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.91850116,51772084,52022029,and U19A2090)Hunan Provincial Natural Science Foundation of China(Grant Nos.2018RS3051 and 2018WK4004)the Key Program of the Hunan Provincial Science and Technology Department,China(Grant No.2019XK2001).
文摘Due to the large exciton binding energy,two-dimensional(2D)transition metal dichalcogenides(TMDCs)provide an ideal platform for studying excitonic states and related photonics and optoelectronics.Polarization states lead to distinct light-matter interactions which are of great importance for device applications.In this work,we study polarized photoluminescence spectra from intralayer exciton and indirect exciton in WS_(2) and WSe_(2) atomic layers,and interlayer exciton in WS_(2)/WSe_(2) heterostructures by radially and azimuthally polarized cylindrical vector laser beams.We demonstrated the same in-plane and out-of-plane polarization behavior from the intralayer and indirect exciton.Moreover,with these two laser modes,we obtained interlayer exciton in WS_(2)/WSe_(2) heterostructures with stronger out-of-plane polarization,due to the formation of vertical electric dipole moment.
文摘A cylindrical vector beam is utilized to enhance the energy scale of the pulse post-compressed in a bulk-material Herriott multi-pass cell(MPC).The method proposed here enables,for the first time to the best of our knowledge,pulse compression from 14 ps down to 475 fs with throughput energy beyond 1 mJ,corresponding to a compression ratio of 30,which is the highest pulse energy and compression ratio in single-stage bulk-material MPCs.Furthermore,we demonstrate the characteristic of the vector polarization beam is preserved in the MPC.
文摘Vector beams with spiral phase and spatially varying polarization profiles have many applications from optical micromanipulation to materials processing. Here, we propose and demonstrate an atomic spatial mode extracting scheme for the vector beam based on polarization-dependent absorption in the atom vapor. By employing the linear polarization pump beam which induces polarization sensitive absorption in the atomic ensemble, a counter-propagated weak probe vector beam is extracted by spatial absorption, and extracted part still maintains the original polarization and the vortex phase.The topological charges of the extracted mode are verified by interfering with the Gaussian beam, and it can be found that the orbital angular momentum is conserved in the extracting process. Our work will have potential applications in non-destructive spatial mode identification, and is also useful for studying higher-dimensional quantum information based on atomic ensembles.
基金Project supported by the National Natural Science Foundation of China(Grant No.11547017)the Hubei Engineering University Research Foundation,China(Grant No.z2014001)the Natural Science Foundation of Hubei Province,China(Grant No.2014CFB578)
文摘We propose a method for generating double-ring-shaped vector beams. A step phase introduced by a spatial light modulator（SLM） first makes the incident laser beam have a nodal cycle. This phase is dynamic in nature because it depends on the optical length. Then a Pancharatnam–Berry phase（PBP） optical element is used to manipulate the local polarization of the optical field by modulating the geometric phase. The experimental results show that this scheme can effectively create double-ring-shaped vector beams. It provides much greater flexibility to manipulate the phase and polarization by simultaneously modulating the dynamic and the geometric phases.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11604050,91636109,61575041,and 61875242)the Fundamental Research Funds for the Central Universities at Xiamen University,China(Grant No.20720190057)+3 种基金the Natural Science Foundation of Fujian Province of China for Distinguished Young Scientists(Grant No.2015J06002)the Program for New Century Excellent Talents in University of China(Grant No.NCET-13-0495)the Science and Technology Planning Project of Guangdong Province,China(Grant No.2016B010113004)the Natural Science Foundation of Guangdong Province,China(Grant Nos.2015A030310296 and 2018A030313347)
文摘We propose a simple and efficient method that uses a single focused hybrid vector beam to confine metallic Rayleigh particles at multiple positions.We study the force mechanisms of multiple trapping by analyzing the gradient and scattering forces.It is observed that the wavelength and topological charges of the hybrid vector beam regulate the trapping positions and number of optical trap sites.The proposed method can be implemented easily in three-dimensional space, and it facilitates both trapping and organization of particles.Thus, it can provide an effective and controllable means for nanoparticle manipulation.
基金National Natural Science Foundation of China(U24A20317,52488301,62192773)West Light Foundation,Chinese Academy of Sciences(xbzg-zdsys-202307)Key Research Program of Frontier Science,Chinese Academy of Sciences(ZDBS-LY-JSC030)。
文摘Polarization detection is essential for various applications,ranging from biological diagnostics to quantum optics.Although various metasurface-based polarimeters have emerged,these platforms are commonly realized through spatial-division designs,which restrict detection accuracy due to inherent factors such as crosstalk.Here,we propose,to our knowledge,a novel strategy for high-accuracy,broadband full-Stokes polarization detection based on the analysis of a single vector beam,whose polarization profile varies sensitively and exhibits a one-to-one correspondence with the incident polarization.Based on this,the incident polarization is completely encoded into the field profile of the vector beam,which avoids crosstalk in principle,and results in high-accuracy polarization detection without any calibration process.As a proof of concept,a geometric-phase metasurface-based grafted perfect vector vortex beam(GPVVB)generator was designed and fabricated.Experimental results demonstrate that our method achieves polarization detection with an average relative error of 2.25%.Benefiting from the broadband high transmittance exceeding 95%of the metasurface due to the femtosecond laser-induced birefringence process,our method operates across a wavelength range of 450–1100 nm.Furthermore,the detection capability of the vector beam polarization profile was validated using a GPVVB-generating array.These results highlight the potential of our approach for transformative applications in polarization detection,including optical communication and machine vision.
基金National Natural Science Foundation of China(62475285,61975235)Natural Science Foundation of Hunan Province(2019JJ40342)。
文摘Broadband polarization measurement plays a crucial role in numerous fields,spanning from fundamental physics to a wide range of practical applications.However,traditional approaches typically rely on combinations of various dispersive optical elements,requiring bulky systems and complicated time-consuming multiple procedures.Here we have achieved broadband spectropolarimetry based on single-shot images for spatial intensity distributions of polychromatic vector beams.A custom-designed diffractive optical element and a vortex retarder convert the incident polychromatic waves into structured vector beams:the former diffracts light of different wavelengths into concentric circles of different radii,while the latter codes their polarization information into intensity distributions along the azimuthal direction.The validation experiments verify our exceptional measurement accuracy(RMS errors<1%)for each Stokes component in the visible light range(400-700 nm),with good spectral(<0.8 nm)and temporal(an output rate of 100 Hz)resolutions.We have further employed our broadband polarimeter to study the mutarotation of glucose,making direct observations of temporal evolutions of chemical reactions accessible.Our work has significantly broadened the toolboxes of spectropolarimetry,which can potentially incubate various disruptive applications that depend on broadband polarization measurements.
基金the financial support from National Natural Science Foundation of China (Nos. 62192771, 12374344, 12221004)National Key Research and Development Program of China (2022YFA1204700, 2020YFA0710100)+1 种基金Natural Science Foundation of Shanghai (Grant No. 23dz2260100)China Postdoctoral Science Foundation 2021TQ0077
文摘On-chip devices for generating pre-designed vectorial optical fields(VOFs)under surface wave(SW)excitations are highly desired in integrated photonics.However,conventional devices are usually of large footprints,low efficiencies,and limited wave-control capabilities.Here,we present a generic approach to design ultra-compact on-chip devices that can efficiently generate pre-designed VOFs under SW excitations,and experimentally verify the concept in terahertz(THz)regime.We first describe how to design SW-excitation metasurfaces for generating circularly polarized complex beams,and experimentally demonstrate two meta-devices to realize directional emission and focusing of THz waves with oppo-site circular polarizations,respectively.We then establish a systematic approach to construct an integrated device via merging two carefully designed metasurfaces,which,under SW excitations,can separately produce pre-designed far-field patterns with different circular polarizations and generate target VOF based on their interference.As a proof of con-cept,we demonstrate experimentally a meta-device that can generate a radially polarized Bessel beam under SW excita-tion at~0.4 THz.Experimental results agree well with full-wave simulations,collectively verifying the performance of our device.Our study paves the road to realizing highly integrated on-chip functional THz devices,which may find many ap-plications in biological sensing,communications,displays,image multiplexing,and beyond.
基金supported by the National Science Foundation(NSF),Division of Material Research(Grant No.DMR-2208240).
文摘Cylindrical vector beams(CVBs),characterized by their spatially varying polarization and axial symmetry,have emerged as powerful tools for engineering light–matter interactions at the nanoscale.Unlike conventional linearly polarized beams,tightly focused CVBs can generate strong longitudinal electric or magnetic field components,enabling the selective excitation of specific multipolar modes and various resulting modes in optical nanostructures.This unique field configuration facilitates the excitation of various optical phenomena such as anapole states,dark modes,Fano resonances,optical magnetism,and enhanced nonlinear optical responses,which are challenging to achieve with traditional illumination.We summarize recent advancements in nanophotonic phenomena/effects driven by CVB excitation,illustrated through seminal studies in plasmonic,dielectric,or hybrid nanostructures,offering promising opportunities for applications in imaging,sensing,optical trapping,quantum information processing,etc.We discuss how enhanced electromagnetic field confinement,increased coupling efficiency,and precise control over resonant scattering can lead to advanced nanophotonic phenomena/effects under CVB illumination.The insights presented here aim to guide future developments in structured light–matter interaction and inspire the design of advanced nanophotonic systems.
文摘Perfect vortices,recognized for their distinct ring profile that remains independent of the topological charge,present significant challenges in generation due to the precise control needed over both phase and polarization.In this work,we introduce and validate a new approach for generating these beams,allowing the selection of diffferent azimuthally-variant phase gradients and vector states,thereby enabling full control over the phase and polarization patterns of perfect vortices.Using dual-functional silicon metaoptics,we achieve the compact generation of a novel class of perfect vortices,termed azimuthally-variant perfect vector beams.The optical characterization of the generated beams,performed through a filtering method,confirms their intrinsic azimuthally-variant vectorial nature.These beams exhibit unique properties that promise valuable applications in optical tweezing,the manipulation of low-refractive-index particles,the trapping of cold atoms,and high-capacity communications.
基金supported by the National Natural Science Foundation of China(No.62075182)the National Key Research and Development Program of China(No.2022YFB3207502)。
文摘We propose a method for generating an all-fiber cylindrical vector beam(CVB)using a fiber Bragg grating(FBG)inscribed in a ring core fiber(RCF).The FBGs are inscribed using the femtosecond laser phase mask scanning technique,chosen for its large ring core diameter and low photosensitivity of the RCF.Additionally,a lateral offset splicing spot is introduced to couple the fundamental mode to the second-order modes.Switchable LP_(01)and LP_(11)mode lasers can be achieved.Meanwhile,azimuthally and radially polarized CVBs are successfully realized by adjusting the polarization controllers.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12033007,61801458,12103058,12203058,12074309,and 61875205)the Key Project of Frontier Science Research of the Chinese Academy of Sciences(Grant No.QYZDB-SSW-SLH007)+2 种基金the Strategic Priority Research Program of CAS(Grant No.XDC07020200)the Youth Innovation Promotion Association,CAS(Grant Nos.2021408,2022413,and 2023425)the Research on Highly Sensitive Long-Wave Receiver Based on Rydberg Atoms(Grant No.1P2024000059)。
文摘The Bessel-like vector vortex beam(BlVVB)has gained increasing significance across numerous applications.However,its practical application is restricted by manufacturing difficulties and polarization manipulation.Thus,the ability to manipulate its degrees of freedom is highly desirable.In this paper,the full-domain polarization modulation of BlVVB within a hot atomic ensemble has been investigated.We begin with the theoretical analysis of the resonant magneto-optical effect of atoms with a horizontal linear-polarized beam and experimentally demonstrate precise manipulation of the polarization state across the entire domain of the BlVVB,achieving an error margin of less than 3°at various cross-sectional points.Our study provides a novel approach for the modulation of BlVVB based on atomic media,which holds potential applications in sensitive vector magnetometers,optical communications,and signal processing.
基金the financial support from the National Key R&D Program of China (2018YFB1107200)the National Natural Science Foundation of China (91750110, 11674130, 61605061, 11674110 and 11874020)+2 种基金the Guangdong Provincial Innovation and Entrepreneurship Project (2016ZT06D081)the Natural Science Foundation of Guangdong Province (2016A030306016, 2016TQ03X981 and 2016A030308010)Pearl River S and T Nova Program of Guangzhou (201806010040)。
文摘The possibility to achieve unprecedented multiplexing of light-matter interaction in nanoscale is of virtue importance from both fundamental science and practical application points of view. Cylindrical vector beams(CVBs) manifested as polarization vortices represent a robust and emerging degree of freedom for information multiplexing with increased capacities. Here, we propose and demonstrate massivelyencoded optical data storage(ODS) by harnessing spatially variant electric fields mediated by segmented CVBs. By tight focusing polychromatic segmented CVBs to plasmonic nanoparticle aggregates, recordhigh multiplexing channels of ODS through different combinations of polarization states and wavelengths have been experimentally demonstrated with a low error rate. Our result not only casts new perceptions for tailoring light-matter interactions utilizing structured light but also enables a new prospective for ultra-high capacity optical memory with minimalist system complexity by combining CVB’s compatibility with fiber optics.
基金National Natural Science Foundation of China(NSFC)(61490710,61705132,61775142)Science and Technology Planning Project of Guangdong Province(2016B050501005)Specialized Research Fund for the Shenzhen Strategic Emerging Industries Development(JCYJ20170412105812811)
文摘This paper reports the experimental realization of efficiently sorting vector beams by polarization topological charge （PTC）. The PTC of a vector beam can be defined as the repetition number of polarization state change along the azimuthal axis, while its sign stands for the rotating direction of the polarization. Here, a couple of liquid crystal Pancharatnam-Berry optical dements （PBOEs） have been used to introduce conjugated spatial phase modulations for two orthogonal circular polarization states. Applying these PBOEs in a 4-foptical system, our experiments show the setup can work for PTC sorting with a separation efficiency of more than 58%. This work provides an effective way to decode information from different PTCs, which may be interesting in many fields, especially in optical communication.
基金supported by the Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.KYCX22_3813)the Jiangsu Province Key Research and Development Program(No.BE2022143)+1 种基金the National Natural Science Foundation of China(No.62205133)the Natural Science Foundation of Jiangsu Province(No.BK20190953).
文摘We reporte and demonstrate a solid-state laser to achieve controlled generation of order-switchable cylindrical vector beams(CVBs).In the cavity,a group of vortex wave plates(VWPs)with two quarter-wave plates between the VWPs was utilized to achieve mode conversion and order-switch of CVBs.By utilizing two VWPs of first and third orders,the second and fourth order CVBs were obtained,with mode purities of 96.8%and 94.8%,and sloping efficiencies of 4.45%and 3.06%,respectively.Furthermore,by applying three VWPs of first,second,and third orders,the mode-switchable Gaussian beam,second,fourth,and sixth order CVBs were generated.
文摘A rotating neodymium-doped yttrium aluminum garnet(Nd:YAG)disk laser resonator for efficiently generating vector beams with azimuthal and radial polarization is demonstrated.In the study,the laser crystal rotary for thermal alleviation and polarization discrimination uses c-cut ytterbium vanadate(YVO_(4)).The laser output could be switched between azimuthal and radial polarizations by simply adjusting the cavity length.The laser power reached 4.38 W and 4.64W for azimuthally and radially polarized beams at the slope efficiencies of 45.3%and 48.5%,respectively.Our study proved that an efficient,high-power vector rotary disk laser would be realistic.
基金supported by the National Natural Science Foundation of China(NSFC)(Nos.11974282 and 91950207)the Doctoral Dissertation Innovation Fund of Northwestern Polytechnical University(No.CX2021039)。
文摘Noble metallic nanostructures with strong electric near-field enhancement can significantly improve nanoscale light-matter interactions and are critical for high-sensitivity surface-enhanced Raman spectroscopy[SERS].Here,we use an azimuthal vector beam[AVB]to illuminate the plasmonic tips circular cluster[PTCC]array to enhance the electric near-field intensity of the PTCC array,and then use it to improve SERS sensitivity.The PTCC array was prepared based on the self-assembled and inductive coupled plasmon[ICP]etching methods.The calculation results show that,compared with the linearly polarized beam[LPB]and radial vector beam excitations,the AVB excitation can obtain stronger electric near-field enhancement due to the strong resonant responses formed in the nanogap between adjacent plasmonic tips.Subsequently,our experimental results proved that AVB excitation increased SERS sensitivity to 10-13mol/L,which is two orders of magnitude higher than that of LPB excitation.Meanwhile,the PTCC array had excellent uniformity with the Raman enhancement factor calculated to be~2.4×10^[8].This kind of vector light field enhancing Raman spectroscopy may be applied in the field of sensing technologies,such as the trace amount detection.
