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)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 simul...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 simulated. Meanwhile, the particle size, wave length and the frequency of the disturbance were compared with the results of linear stability analysis. The results showed that even though the fluid becomes discontinuous, the traditional linear stability analysis can be used to make a rough calculation of the nanojet break-up.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 simulated. Meanwhile, the particle size, wave length and the frequency of the disturbance were compared with the results of linear stability analysis. The results showed that even though the fluid becomes discontinuous, the traditional linear stability analysis can be used to make a rough calculation of the nanojet break-up.
