scholarly journals Plasmonic interference modulation for broadband nanofocusing

Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Shaobo Li ◽  
Shuming Yang ◽  
Fei Wang ◽  
Qiang Liu ◽  
Biyao Cheng ◽  
...  
Keyword(s):  
Near Field ◽  
Three Dimensional ◽  
Field Enhancement ◽  
Incident Beam ◽  
Plasmonic Mode ◽  
Resonant Structures ◽  
Interference Modulation ◽  
Near Field Imaging ◽  
Linearly Polarized ◽  
Radially Polarized

Abstract Metallic plasmonic probes have been successfully applied in near-field imaging, nanolithography, and Raman enhanced spectroscopy because of their ability to squeeze light into nanoscale and provide significant electric field enhancement. Most of these probes rely on nanometric alignment of incident beam and resonant structures with limited spectral bandwidth. This paper proposes and experimentally demonstrates an asymmetric fiber tip for broadband interference nanofocusing within its full optical wavelengths (500–800 nm) at the nanotip with 10 nm apex. The asymmetric geometry consisting of two semicircular slits rotates plasmonic polarization and converts the linearly polarized plasmonic mode to the radially polarized plasmonic mode when the linearly polarized beam couples to the optical fiber. The three-dimensional plasmonic modulation induces circumference interference and nanofocus of surface plasmons, which is significantly different from the nanofocusing through plasmon propagation and plasmon evolution. The plasmonic interference modulation provides fundamental insights into the plasmon engineering and has important applications in plasmon nanophotonic technologies.

Three-Dimensional Finite-Difference Time-Domain Method Modeling of Nanowire Optical Probe

2014 ◽  
Vol 602-605 ◽  
pp. 3359-3362
Author(s):  
Chun Li Zhu ◽  
Jing Li
Keyword(s):  
Finite Difference ◽  
Time Domain ◽  
Finite Difference Time Domain ◽  
Incident Light ◽  
Near Field ◽  
Three Dimensional ◽  
Polarization Direction ◽  
Near Field Imaging ◽  
Difference Time ◽  
Field Imaging

In this paper, output near fields of nanowires with different optical and structure configurations are calculated by using the three-dimensional finite-difference time-domain (3D FDTD) method. Then a nanowire with suitable near field distribution is chosen as the probe for scanning dielectric and metal nanogratings. Scanning results show that the resolution in near-field imaging of dielectric nanogratings can be as low as 80nm, and the imaging results are greatly influenced by the polarization direction of the incident light. Compared with dielectric nanogratings, metal nanogratings have significantly enhanced resolutions when the arrangement of gratings is perpendicular to the polarization direction of the incident light due to the enhancement effect of the localized surface plasmons (SPs). Results presented here could offer valuable references for practical applications in near-field imaging with nanowires as optical probes.

Effect of Substrate and Nanoparticle Spacing on Plasmonic Enhancement in Three-Dimensional Nanoparticle Structures

2017 ◽  
Vol 5 (4) ◽  
Author(s):  
Anil Yuksel ◽  
Edward T. Yu ◽  
Jayathi Murthy ◽  
Michael Cullinan
Keyword(s):  
Near Field ◽  
Three Dimensional ◽  
Polarized Light ◽  
Field Enhancement ◽  
Transverse Magnetic ◽  
Plasmonic Enhancement ◽  
Nanoparticle Assemblies ◽  
Nanoparticle Interactions ◽  
Gap Spacing ◽  
532 Nm

Surface plasmon polaritons associated with light-nanoparticle interactions can result in dramatic enhancement of electromagnetic fields near and in the gaps between the particles, which can have a large effect on the sintering of these nanoparticles. For example, the plasmonic field enhancement within nanoparticle assemblies is affected by the particle size, spacing, interlayer distance, and light source properties. Computational analysis of plasmonic effects in three-dimensional (3D) nanoparticle packings are presented herein using 532 nm plane wave light. This analysis provides insight into the particle interactions both within and between adjacent layers for multilayer nanoparticle packings. Electric field enhancements up to 400-fold for transverse magnetic (TM) or X-polarized light and 26-fold for transverse electric (TE) or Y-polarized light are observed. It is observed that the thermo-optical properties of the nanoparticle packings change nonlinearly between 0 and 10 nm gap spacing due to the strong and nonlocal near-field interaction between the particles for TM polarized light, but this relationship is linear for TE polarized light. These studies help provide a foundation for understanding micro/nanoscale heating and heat transport for Cu nanoparticle packings under 532 nm light under different polarization for the photonic sintering of nanoparticle assemblies.

Radially Polarized Annular-Slot Leaky-Wave Antenna for Three-Dimensional Near-Field Microwave Focusing

2014 ◽  
Vol 13 ◽  
pp. 583-586 ◽  
Author(s):  
Darwin Blanco ◽  
Jose Luis Gomez-Tornero ◽  
Eva Rajo-Iglesias ◽  
Nuria Llombart
Keyword(s):  
Near Field ◽  
Three Dimensional ◽  
Leaky Wave ◽  
Annular Slot ◽  
Leaky Wave Antenna ◽  
Wave Antenna ◽  
Radially Polarized

scholarly journals Near-field enhancement and imaging in double planar polariton-resonant structures

2004 ◽  
Vol 96 (3) ◽  
pp. 1293-1300 ◽  
Author(s):  
Stanislav Maslovski ◽  
Sergei Tretyakov ◽  
Pekka Alitalo
Keyword(s):  
Near Field ◽  
Field Enhancement ◽  
Resonant Structures

scholarly journals Modifying Plasmonic-Field Enhancement and Resonance Characteristics of Spherical Nanoparticles on Metallic Film: Effects of Faceting Spherical Nanoparticle Morphology

Coatings ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 387 ◽  
Author(s):  
Vasanthan Devaraj ◽  
Hyuk Jeong ◽  
Chuntae Kim ◽  
Jong-Min Lee ◽  
Jin-Woo Oh
Keyword(s):  
Near Infrared ◽  
Near Field ◽  
Three Dimensional ◽  
Field Enhancement ◽  
Device Fabrication ◽  
Metallic Film ◽  
Linear Optics ◽  
Cross Sectional ◽  
Non Linear Optics ◽  
Surface Enhanced

A three-dimensional finite-difference time-domain study of the plasmonic structure of nanoparticles on metallic film (NPOM) is presented in this work. An introduction to nanoparticle (NP) faceting in the NPOM structure produced a variety of complex transverse cavity modes, which were labeled S11 to S13. We observed that the dominant S11 mode resonance could be tuned to the desired wavelength within a broadband range of ~800 nm, with a maximum resonance up to ~1.42 µm, as a function of NP facet width. Despite being tuned at the broad spectral range, the S11 mode demonstrated minimal decrease in its near field enhancement characteristics, which can be advantageous for surface-enhanced spectroscopy applications and device fabrication perspectives. The identification of mode order was interpreted using cross-sectional electric field profiles and three-dimensional surface charge mapping. We realized larger local field enhancement in the order of ~109, even for smaller NP diameters of 50 nm, as function of the NP faceting effect. The number of radial modes were dependent upon the combination of NP diameter and faceting length. We hope that, by exploring the sub-wavelength complex optical properties of the plasmonic structures of NPOM, a variety of exciting applications will be revealed in the fields of sensors, non-linear optics, device engineering/processing, broadband tunable plasmonic devices, near-infrared plasmonics, and surface-enhanced spectroscopy.

Simulation of Electromagnetic Field Distribution at a Nanowire Probe for Near Field Scanning Optical Microscopy

2008 ◽  
Author(s):  
Nathan P. Malcolm ◽  
Alex J. Heltzel ◽  
Li Shi ◽  
John R. Howell
Keyword(s):  
Optical Microscopy ◽  
Signal To Noise Ratio ◽  
Near Field ◽  
Three Dimensional ◽  
Field Enhancement ◽  
Fdtd Simulation ◽  
Plasmonic Nanoparticle ◽  
Excitation Laser ◽  
Scanning Optical Microscopy ◽  
Near Field Scanning

This work studies a new design of a near field scanning optical microscopy (NSOM) probe based on a ZnO nanowire sub-wavelength waveguide terminated with a plasmonic gold nanoparticle. Three-dimensional finite difference time domain (FDTD) simulation is used to visualize light guiding in the nanowire and near field coupling between the plasmonic nanoparticle and the substrate. The simulation results reveal local field enhancement at the gap between the nanoparticle and a gold substrate when the nanowire axis is tilted from the substrate normal by a small angle. The enhancement occurs only along the cross section plane that is parallel to the polarization of the excitation laser beam. The regime of field enhancement is much smaller than the diameter of the 100 nm plasmonic particle, making the nanowire probe well suited for NSOM with superior spatial resolution and signal to noise ratio compared to the state of the art.

scholarly journals Near-Field Diffraction from a Binary Microaxicon

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Victor V. Kotlyar ◽  
Sergey S. Stafeev ◽  
Roman V. Skidanov ◽  
Victor A. Soifer
Keyword(s):  
Finite Difference ◽  
Focal Spot ◽  
Optical Axis ◽  
Near Field ◽  
Three Dimensional ◽  
Finite Difference Schemes ◽  
Cylindrical Coordinates ◽  
Linearly Polarized ◽  
Experimental Values ◽  
Good Agreement

We study binary axicons of period 4, 6, and 8 μm fabricated by photolithography with a 1 μm resolution, 500 nm depth, and 4 mm diameter. Near-field diffraction focal spots varying in diameter from 3.5λ to 4.5λ (for the axicon of period T=4 μm) and from 5λ to 8λ (for the axicon with T=8 μm) are experimentally found on the optical axis at a distance of up to 40 μm from the axicon for the wavelength λ=0.532 μm. The first focal spot is found at distance 2 μm (T=4 μm), with the period of the focal spots being 2 μm (T=4 μm) and 4 μm (T=8 μm). Diffraction of linearly polarized plane and diverging waves is simulated using FullWAVE (RSoft) and a proprietary program BOR-FDTD, which implement finite-difference schemes to solve three-dimensional Maxwell's equations in the Cartesian and cylindrical coordinates. The numerically simulated values for diameters of the near-field focal spots for the axicon of period T=4 μm are in good agreement with the experimental values.

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