The properties of the photonic nanojet generated by a two-layer dielectric microsphere are studied. Simulation results indicate that this novel structure can generate a photonic nanojet outside its volume when the ref...The properties of the photonic nanojet generated by a two-layer dielectric microsphere are studied. Simulation results indicate that this novel structure can generate a photonic nanojet outside its volume when the refractive index contrast relative to the background medium is higher than 2：1 in the condition of plane wave incidence. When the refractive index is smaller than 2, we show that an ultralong nanojet generated by the two-layer hemisphere has an extension of 28.2 wavelengths, and compared with the homogeneous dielectric hemisphere, it has superior performance in jet length and focal distance. Its dependence on the configuration and refractive index is investigated numerically. According to the simulation of the two-layer dielectric microsphere, a photonic nanojet with a full width at half maximum（FWHM） less than 1/2 wavelength is obtained and the tunable behaviors of the photonic nanojet are demonstrated by changing the reflective indices of the material or radius contrast ratio.展开更多
Photonic nanojets(PNJs) have a wide range of applications in laser processing, nanolithography, optical highdensity storage, super-resolution microscopy, and other fields due to their processing capacity to overcome t...Photonic nanojets(PNJs) have a wide range of applications in laser processing, nanolithography, optical highdensity storage, super-resolution microscopy, and other fields due to their processing capacity to overcome the diffraction limit. Herein, we control static microsphere be developed into the motion state to fabricate vector graphics nano-grooves.The microspheres roll on the substrate while the laser is kept synchronously irradiated, and the overlapping PNJ ablated craters form patterned grooves on the indium-tin oxide(ITO) substrate. Thus, PNJ has been expanded from “point”processing to “line” processing. The fabricated nano grooves have high continuity and consistency. Whereas, the precise customization of critical groove dimension can be achieved via modulation in diameter and kinetics of dielectric microshperes. Furthermore, by etching vectographs on an ITO conductive glass substrate, we demonstrated the advantages and potential of the proposed method in nanopatterning. The proposed method effectively reduces the cost and complexity of photonic nanojets applied in nanopatterning. The proposed nanopatterning methodology will play a vital role in the fabrication of semiconductor materials, sensors, microfluidic devices, surface-enhanced Raman scattering(SERS), biomedicine, nanoscience and nanoengineering.展开更多
Photonic nanojets(PNJs)are subwavelength jet-like propagating waves generated by illuminating a dielectric microstructure with an electromagnetic wave,conventionally a linearly polarized plane wave.Here,we study the d...Photonic nanojets(PNJs)are subwavelength jet-like propagating waves generated by illuminating a dielectric microstructure with an electromagnetic wave,conventionally a linearly polarized plane wave.Here,we study the donut-like PNJ produced when a circularly polarized vortex beam is used instead.This novel PNJ also has a reverse energy flow at the donut-like focal plane depending on both the optical vortex topological charge and microsphere size.Our tunable PNJ,which we investigate numerically and analytically,can find applications in optical micromanipulation and trapping.展开更多
In this paper the liquid argon nanojet break-up phenomenon was studied using the molecular dynamics method. The effects of temperature, nozzle diameter and body force on the nanojet break-up length and time were simu-...In this paper the liquid argon nanojet break-up phenomenon was studied using the molecular dynamics method. The effects of temperature, nozzle diameter and body force on the nanojet break-up length and time were simu- lated. Meanwhile, the particle size, wave length and the frequency of the disturbance were compared with the re- suits of linear stability analysis. The results showed that even though the fluid becomes discontinuous, the tradi- tional linear stability analysis can be used to make a rough calculation of the nanojet break-up.展开更多
Although optical microscopy is a widely used technique across various multidisciplinary fields for inspecting small-scale objects,surfaces or organisms,it faces a significant limitation:the lateral resolution of optic...Although optical microscopy is a widely used technique across various multidisciplinary fields for inspecting small-scale objects,surfaces or organisms,it faces a significant limitation:the lateral resolution of optical microscopes is fundamentally constrained by light diffraction.Dielectric micro-spheres,however,offer a promising solution to this issue as they are capable of significantly enhancing lateral resolution through extraordinary phenomena,such as a photonic nanojet.Building upon the potential of dielectric micro-spheres,this paper introduces a novel approach for fabricating 3D micro-devices designed to enhance lateral resolution in optical microscopy.The proposed 3D micro-device comprises a modified coverslip and a micro-sphere,facilitating easy handling and integration into any existing optical microscope.To manufacture the device,two advanced femtosecond laser techniques are employed:femtosecond laser ablation and multi-photon lithography.Femtosecond laser ablation was employed to create a micro-hole in the coverslip,which allows light to be focused through this aperture.Multi-photon lithography was used to fabricate a micro-sphere with a diameter of 20μm,along with a cantilever that positions the above the processed micro-hole and connect it with the coverslip.In this context,advanced processing strategies for multi-photon lithography to produce a micro-sphere with superior surface roughness and almost perfect geometry(λ/8)from a Zr-based hybrid photoresist are demonstrated.The performance of the micro-device was evaluated using Mirau-type coherence scanning interferometry in conjunction with white light illumination at a central wavelength of 600 nm and a calibration grid(Λ=0.28μm,h>50 nm).Here,the 3D micro-device proved to be capable of enhancing lateral resolution beyond the limits achievable with conventional lenses or microscope objectives when used in air.Simultaneously,it maintained the high axial resolution characteristic of Mirau-type coherence scanning interferometry.The results and optical properties of the micro-sphere were analyzed and further discussed through simulations.展开更多
基金Project supported by State Key Laboratory of Optical Technologies on Nano-Fabrication and Micro-Engineering,Institute of Optics and Electronics,Chinese Academy of SciencesSichuan Provincial Department of Education,China(Grant No.16ZA0047)+1 种基金the State Key Laboratory of Metastable Materials Science and Technology,Yansan University,China(Grant No.201509)the Large Precision Instruments Open Project Foundation of Sichuan Normal University,China(Grant Nos.DJ2015-57,DJ2015-58,DJ2015-60,DJ2016-58,and DJ2016-59)
文摘The properties of the photonic nanojet generated by a two-layer dielectric microsphere are studied. Simulation results indicate that this novel structure can generate a photonic nanojet outside its volume when the refractive index contrast relative to the background medium is higher than 2：1 in the condition of plane wave incidence. When the refractive index is smaller than 2, we show that an ultralong nanojet generated by the two-layer hemisphere has an extension of 28.2 wavelengths, and compared with the homogeneous dielectric hemisphere, it has superior performance in jet length and focal distance. Its dependence on the configuration and refractive index is investigated numerically. According to the simulation of the two-layer dielectric microsphere, a photonic nanojet with a full width at half maximum（FWHM） less than 1/2 wavelength is obtained and the tunable behaviors of the photonic nanojet are demonstrated by changing the reflective indices of the material or radius contrast ratio.
基金Projects(LZ20E050003, LD22E050001) supported by the Zhejiang Provincial Natural Science Foundation of China。
文摘Photonic nanojets(PNJs) have a wide range of applications in laser processing, nanolithography, optical highdensity storage, super-resolution microscopy, and other fields due to their processing capacity to overcome the diffraction limit. Herein, we control static microsphere be developed into the motion state to fabricate vector graphics nano-grooves.The microspheres roll on the substrate while the laser is kept synchronously irradiated, and the overlapping PNJ ablated craters form patterned grooves on the indium-tin oxide(ITO) substrate. Thus, PNJ has been expanded from “point”processing to “line” processing. The fabricated nano grooves have high continuity and consistency. Whereas, the precise customization of critical groove dimension can be achieved via modulation in diameter and kinetics of dielectric microshperes. Furthermore, by etching vectographs on an ITO conductive glass substrate, we demonstrated the advantages and potential of the proposed method in nanopatterning. The proposed method effectively reduces the cost and complexity of photonic nanojets applied in nanopatterning. The proposed nanopatterning methodology will play a vital role in the fabrication of semiconductor materials, sensors, microfluidic devices, surface-enhanced Raman scattering(SERS), biomedicine, nanoscience and nanoengineering.
基金supported by the National Key R&D Program of China(Nos.2018YFA0306200 and 2017YFA0303700)the National Natural Science Foundation of China(NSFC)(Nos.91750202,61805119,61604073,and 11404170)+1 种基金the Natural Science Foundation of Jiangsu Province of China(Nos.BK20160839 and BK20180469)the Scientific Research Project of Nanjing University of Posts and Telecommunications(No.NY219045)。
文摘Photonic nanojets(PNJs)are subwavelength jet-like propagating waves generated by illuminating a dielectric microstructure with an electromagnetic wave,conventionally a linearly polarized plane wave.Here,we study the donut-like PNJ produced when a circularly polarized vortex beam is used instead.This novel PNJ also has a reverse energy flow at the donut-like focal plane depending on both the optical vortex topological charge and microsphere size.Our tunable PNJ,which we investigate numerically and analytically,can find applications in optical micromanipulation and trapping.
文摘In this paper the liquid argon nanojet break-up phenomenon was studied using the molecular dynamics method. The effects of temperature, nozzle diameter and body force on the nanojet break-up length and time were simu- lated. Meanwhile, the particle size, wave length and the frequency of the disturbance were compared with the re- suits of linear stability analysis. The results showed that even though the fluid becomes discontinuous, the tradi- tional linear stability analysis can be used to make a rough calculation of the nanojet break-up.
基金supported by the Marie Skłodowska-Curie Actions,under grant agreement No.101059253,as part of the European Union’s Horizon Europe research and innovation programmeIt also received support from a Feodor Lynen Postdoctoral Fellowship awarded by the Alexander von Humboldt Foundation.Additional funding was provided by Laserlab-Europe(Proposal IDs:ULF-FORTH_002794 and ULF-FORTH_025264).We further gratefully acknowledge funding by the German Federal Ministry for Economic Affairs and Climate Action under grant 16KN053050.The authors would also like to thank Mrs.Aleka Manousaki for SEM technical support.
文摘Although optical microscopy is a widely used technique across various multidisciplinary fields for inspecting small-scale objects,surfaces or organisms,it faces a significant limitation:the lateral resolution of optical microscopes is fundamentally constrained by light diffraction.Dielectric micro-spheres,however,offer a promising solution to this issue as they are capable of significantly enhancing lateral resolution through extraordinary phenomena,such as a photonic nanojet.Building upon the potential of dielectric micro-spheres,this paper introduces a novel approach for fabricating 3D micro-devices designed to enhance lateral resolution in optical microscopy.The proposed 3D micro-device comprises a modified coverslip and a micro-sphere,facilitating easy handling and integration into any existing optical microscope.To manufacture the device,two advanced femtosecond laser techniques are employed:femtosecond laser ablation and multi-photon lithography.Femtosecond laser ablation was employed to create a micro-hole in the coverslip,which allows light to be focused through this aperture.Multi-photon lithography was used to fabricate a micro-sphere with a diameter of 20μm,along with a cantilever that positions the above the processed micro-hole and connect it with the coverslip.In this context,advanced processing strategies for multi-photon lithography to produce a micro-sphere with superior surface roughness and almost perfect geometry(λ/8)from a Zr-based hybrid photoresist are demonstrated.The performance of the micro-device was evaluated using Mirau-type coherence scanning interferometry in conjunction with white light illumination at a central wavelength of 600 nm and a calibration grid(Λ=0.28μm,h>50 nm).Here,the 3D micro-device proved to be capable of enhancing lateral resolution beyond the limits achievable with conventional lenses or microscope objectives when used in air.Simultaneously,it maintained the high axial resolution characteristic of Mirau-type coherence scanning interferometry.The results and optical properties of the micro-sphere were analyzed and further discussed through simulations.
