Optical trapping has revolutionized various scientific disciplines with its non-invasive,high-resolution manipulation capabilities.However,conventional optical tweezers face limitations in effectively manipulating met...Optical trapping has revolutionized various scientific disciplines with its non-invasive,high-resolution manipulation capabilities.However,conventional optical tweezers face limitations in effectively manipulating metallic particles due to their high reflectivity and associated scattering forces.Plasmonic tweezers,harnessing surface plasmons in metallic nanostructures,offer a promising solution by confining light to deep subwavelength scales and enhancing optical forces.However,dynamically manipulating metallic particles with plasmonic tweezers without mechanical adjustments remains a significant challenge.In this paper,we propose a novel approach utilizing dynamic optical tweezers with tunable plasmonic fields for metallic particle manipulation.By dynamically tailoring plasmonic fields with holograms,metallic particles can be manipulated without mechanical adjustments.Finite-difference timedomain simulations and Maxwell stress tensor calculations demonstrate the effectiveness of this technique,which offers simplicity,precision,and motionlessness in metallic particle manipulation.This advancement holds promise for applications in surface-enhanced Raman scattering,biosensing,super-resolved detection,and nanoparticle assembly,opening new avenues in plasmonic tweezers technology.展开更多
Phase and polarization singularities are important degrees of freedom for electromagnetic field manipulation.Detecting these singularities is essential for modern optics,but it is still a challenge,especially in integ...Phase and polarization singularities are important degrees of freedom for electromagnetic field manipulation.Detecting these singularities is essential for modern optics,but it is still a challenge,especially in integrated optical systems.In this paper,we propose an on-chip plasmonic spin-Hall nanograting structure that simultaneously detects both the polarization and phase singularities of the incident cylindrical vortex vector beam(CVVB).The nanograting is symmetry-breaking with different periods for the upper and lower parts,which enables the unidirectional excitation of the surface plasmon polariton depending on the topological charge of the incident optical vortex beam.Additionally,spin-Hall meta-slits are integrated onto the grating so that the structure has a chiral response for polarization detection.We demonstrate theoretically and experimentally that the designed structure fully discriminates both the topological charges and polarization states of the incident beam simultaneously.The proposed structure has great potential in compact integrated photonic circuits.展开更多
As disease diagnosis becomes more sophisticated,there is a requirement to measure small numbers of molecules attached to,for instance,an antibody.This requires a sensor capable not only of high sensitivity but also th...As disease diagnosis becomes more sophisticated,there is a requirement to measure small numbers of molecules attached to,for instance,an antibody.This requires a sensor capable not only of high sensitivity but also the ability to make measurements over a highly localized region.In previous publications,we have shown how a modified confocal microscope allows one to make localized surface plasmon(SP)measurements on a scale far smaller than the surface plasmon propagation distance.The present implementation presents a new ultrastable interferometer system,which greatly improves the noise performance.Hitherto,we have used the central part of the back focal plane to form a reference beam with the reradiated surface plasmons.In the current system,we block the central part and use the spatial light modulator to deflect s-polarized light into the pinhole to form an interference signal with the surface plasmons,thus creating an ultrastable interferometer formed with two beams incident at very similar angles.We demonstrate the superior noise performance of the system in hostile environments and examine further adaptations of the system to further enhance noise performance.展开更多
Flat lenses thinner than a wavelength promise to replace conventional refractive lenses in miniaturized optical systems.However,Fresnel zone plate flat lens designs require dense annuli,which significantly challenges ...Flat lenses thinner than a wavelength promise to replace conventional refractive lenses in miniaturized optical systems.However,Fresnel zone plate flat lens designs require dense annuli,which significantly challenges nanofabrication resolution.Herein,we propose a new implementation of detour phase graphene flat lens with flexible annular number and width.Several graphene metalenses demonstrated that with a flexible selection of the line density and width,the metalenses can achieve the same focal length without significant distortions.This will significantly weaken the requirement of the nanofabrication system which is important for the development of large-scale flat lenses in industry applications.展开更多
Owing to their unique optical properties and new degrees of freedom,orbital angular momentum(OAM)beams have been applied in various fields.Detection of the topological charges(TCs)of OAM beams is the key step for thei...Owing to their unique optical properties and new degrees of freedom,orbital angular momentum(OAM)beams have been applied in various fields.Detection of the topological charges(TCs)of OAM beams is the key step for their applications.However,on-chip sorting of OAM beams with large TCs still remains a challenge.In this paper,Bloch surface wave(BSW)structures with five semi-ring shaped nanoslits are modeled.A spatial separation of 135 nm on the chip is obtained between two neighboring OAM states.OAM beams with TCs up to 35 can be successfully sorted by the BSW structures,which is much larger than that using metallic structures(only seven).BSW structures exhibit better OAM sorting performances than metallic structures.We systematically show how the lower attenuation of BSW structures leads to far superior separation ability compared to surface plasmons propagating on metallic structures.In addition,sorting of two OAM beams with different TCs simultaneously can be achieved in this way.Our results reveal that BSW structures should be an excellent solution for OAM sorting with large TCs,which is beneficial for applications in integrated on-chip devices and optical communications.展开更多
基金National Natural Science Foundation of China(62175162)Scientific Instrument Developing Project of Shenzhen University(2023YQ001)+1 种基金Shenzhen University 2035 Program for Excellent Research(2022C013)Research Team Cultivation Program of Shenzhen University(2023QNT012).
文摘Optical trapping has revolutionized various scientific disciplines with its non-invasive,high-resolution manipulation capabilities.However,conventional optical tweezers face limitations in effectively manipulating metallic particles due to their high reflectivity and associated scattering forces.Plasmonic tweezers,harnessing surface plasmons in metallic nanostructures,offer a promising solution by confining light to deep subwavelength scales and enhancing optical forces.However,dynamically manipulating metallic particles with plasmonic tweezers without mechanical adjustments remains a significant challenge.In this paper,we propose a novel approach utilizing dynamic optical tweezers with tunable plasmonic fields for metallic particle manipulation.By dynamically tailoring plasmonic fields with holograms,metallic particles can be manipulated without mechanical adjustments.Finite-difference timedomain simulations and Maxwell stress tensor calculations demonstrate the effectiveness of this technique,which offers simplicity,precision,and motionlessness in metallic particle manipulation.This advancement holds promise for applications in surface-enhanced Raman scattering,biosensing,super-resolved detection,and nanoparticle assembly,opening new avenues in plasmonic tweezers technology.
基金partially supported by the National Natural Science Foundation of China(91750205,U1701661,61935013,61905147)Leading Talents Program of Guangdong Province(00201505,2019JC01Y178)+2 种基金Natural Science Foundation of Guangdong Province(2016A030312010,2020A1515010598)Shenzhen Science and Technology Innovation Commission(JCYJ20180507182035270,KQTD2017033011044403,KQTD20180412181324255)Shenzhen university starting funding(2019073).
文摘Phase and polarization singularities are important degrees of freedom for electromagnetic field manipulation.Detecting these singularities is essential for modern optics,but it is still a challenge,especially in integrated optical systems.In this paper,we propose an on-chip plasmonic spin-Hall nanograting structure that simultaneously detects both the polarization and phase singularities of the incident cylindrical vortex vector beam(CVVB).The nanograting is symmetry-breaking with different periods for the upper and lower parts,which enables the unidirectional excitation of the surface plasmon polariton depending on the topological charge of the incident optical vortex beam.Additionally,spin-Hall meta-slits are integrated onto the grating so that the structure has a chiral response for polarization detection.We demonstrate theoretically and experimentally that the designed structure fully discriminates both the topological charges and polarization states of the incident beam simultaneously.The proposed structure has great potential in compact integrated photonic circuits.
基金Engineering and Physical Sciences Research Council
文摘As disease diagnosis becomes more sophisticated,there is a requirement to measure small numbers of molecules attached to,for instance,an antibody.This requires a sensor capable not only of high sensitivity but also the ability to make measurements over a highly localized region.In previous publications,we have shown how a modified confocal microscope allows one to make localized surface plasmon(SP)measurements on a scale far smaller than the surface plasmon propagation distance.The present implementation presents a new ultrastable interferometer system,which greatly improves the noise performance.Hitherto,we have used the central part of the back focal plane to form a reference beam with the reradiated surface plasmons.In the current system,we block the central part and use the spatial light modulator to deflect s-polarized light into the pinhole to form an interference signal with the surface plasmons,thus creating an ultrastable interferometer formed with two beams incident at very similar angles.We demonstrate the superior noise performance of the system in hostile environments and examine further adaptations of the system to further enhance noise performance.
基金Natural Science Foundation of Guangdong Province(2016A030310130)Australia Research Council(the Discovery Project scheme)(DP190103186)+5 种基金Australian Research Council Industrial Transformation Training Centre for Functional Grains(IC180100005)National Natural Science Foundation of China(62175162)Foundation of Shenzhen Science and Technology(20200814100534001)Science,Technology and Innovation Commission of Shenzhen Municipality(KQTD20170330110444030,KQTD20180412181324255)Foundation of Guangdong Education Committee(2020KTSCX117)China Postdoctoral Science Foundation(2021M692173)。
文摘Flat lenses thinner than a wavelength promise to replace conventional refractive lenses in miniaturized optical systems.However,Fresnel zone plate flat lens designs require dense annuli,which significantly challenges nanofabrication resolution.Herein,we propose a new implementation of detour phase graphene flat lens with flexible annular number and width.Several graphene metalenses demonstrated that with a flexible selection of the line density and width,the metalenses can achieve the same focal length without significant distortions.This will significantly weaken the requirement of the nanofabrication system which is important for the development of large-scale flat lenses in industry applications.
基金National Natural Science Foundation of China(61905147,61935013,62175157,62275167,92250304)Natural Science Foundation of Guangdong Province(2020A1515010598)+2 种基金Center-initiated Research Project of Zhejiang Lab(113014-AL2209)Science,Technology and Innovation Commission of Shenzhen Municipality(20200803150227003,RCJC20210609103232046)China Postdoctoral Science Foundation(2022M710097)。
文摘Owing to their unique optical properties and new degrees of freedom,orbital angular momentum(OAM)beams have been applied in various fields.Detection of the topological charges(TCs)of OAM beams is the key step for their applications.However,on-chip sorting of OAM beams with large TCs still remains a challenge.In this paper,Bloch surface wave(BSW)structures with five semi-ring shaped nanoslits are modeled.A spatial separation of 135 nm on the chip is obtained between two neighboring OAM states.OAM beams with TCs up to 35 can be successfully sorted by the BSW structures,which is much larger than that using metallic structures(only seven).BSW structures exhibit better OAM sorting performances than metallic structures.We systematically show how the lower attenuation of BSW structures leads to far superior separation ability compared to surface plasmons propagating on metallic structures.In addition,sorting of two OAM beams with different TCs simultaneously can be achieved in this way.Our results reveal that BSW structures should be an excellent solution for OAM sorting with large TCs,which is beneficial for applications in integrated on-chip devices and optical communications.
