Near-field and far-field modeling of scattered surface waves. Application to the apertureless scanning near-field optical microscopy

2011 ◽  
Vol 112 (7) ◽  
pp. 1162-1169 ◽  
Author(s):  
J. Muller ◽  
G. Parent ◽  
S. Fumeron ◽  
G. Jeandel ◽  
D. Lacroix
Keyword(s):  
Surface Waves ◽  
Optical Microscopy ◽  
Near Field ◽  
Far Field ◽  
Field Modeling

Far field modeling of the Mamala Bay outfalls

1998 ◽  
Vol 38 (10) ◽  
pp. 323-330
Author(s):  
Philip J. W. Roberts
Keyword(s):  
Field Model ◽  
Near Field ◽  
Far Field ◽  
Field Modeling ◽  
Visitation Frequency ◽  
Statistical Variation ◽  
Long Time ◽  
Harmonic Average ◽  
Ocean Outfall ◽  
Acoustic Doppler Current Profilers

The results of far field modeling of the wastefield formed by the Sand Island, Honolulu, ocean outfall are presented. A far field model, FRFIELD, was coupled to a near field model, NRFIELD. The input data for the models were long time series of oceanographic observations over the whole water column including currents measured by Acoustic Doppler Current Profilers and density stratification measured by thermistor strings. Thousands of simulations were made to predict the statistical variation of wastefield properties around the diffuser. It was shown that the visitation frequency of the wastefield decreases rapidly with distance from the diffuser. The spatial variation of minimum and harmonic average dilutions was also predicted. Average dilution increases rapidly with distance. It is concluded that any impact of the discharge will be confined to a relatively small area around the diffuser and beach impacts are not likely to be significant.

Near-field optical and atomic force constraints for superresolution 3D deconvolution in far-field optical microscopy

2000 ◽  
Author(s):  
Noel Axelrod ◽  
Anna Radko ◽  
Nissim Ben-Yosef ◽  
Artium Khatchatouriants ◽  
Millet Treinin ◽  
...  
Keyword(s):  
Optical Microscopy ◽  
Near Field ◽  
Far Field ◽  
Atomic Force

scholarly journals Helicity-delinked manipulations on surface waves and propagating waves by metasurfaces

Nanophotonics ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 3473-3481 ◽  
Author(s):  
Shiqing Li ◽  
Zhuo Wang ◽  
Shaohua Dong ◽  
Sixiong Yi ◽  
Fuxin Guan ◽  
...  
Keyword(s):  
Surface Waves ◽  
Near Field ◽  
Far Field ◽  
Proof Of Concept ◽  
Circularly Polarized ◽  
Propagating Waves ◽  
Very High ◽  
Opposite Helicity

AbstractAlthough many approaches have been proposed to manipulate propagating waves (PWs) and surface waves (SWs), usually each operation needs a separate meta-device, being unfavorable for optical integrations. Here, we propose a scheme to design a single meta-device that can efficiently generate SWs and/or PWs with pre-designed wavefronts, under the excitations of circularly polarized (CP) PWs with different helicity. As a proof of concept, we design and fabricate a microwave meta-device and experimentally demonstrate that it can convert incident CP waves of opposite helicity to SWs possessing different wavefronts and traveling to opposite directions, both exhibiting very high efficiencies. We further generalize our scheme to design a meta-device and numerically demonstrate that it can either excite a SW beam with tailored wavefront or generate a far-field PW with pre-designed wavefront, as shined by CP waves with different helicity. Our work opens the door to achieving simultaneous controls on far- and near-field electromagnetic environments based on a single ultra-compact platform.

scholarly journals k-space imaging of the eigenmodes of sharp gold tapers for scanning near-field optical microscopy

2013 ◽  
Vol 4 ◽  
pp. 603-610 ◽  
Author(s):  
Martin Esmann ◽  
Simon F Becker ◽  
Bernard B da Cunha ◽  
Jens H Brauer ◽  
Ralf Vogelgesang ◽  
...  
Keyword(s):  
Spatial Frequency ◽  
Optical Microscopy ◽  
Frequency Domain ◽  
Near Field ◽  
Higher Order ◽  
Far Field ◽  
Radiation Patterns ◽  
Background Ratio ◽  
Higher Order Modes ◽  
Spatial Frequency Domain

We investigate the radiation patterns of sharp conical gold tapers, which were designed as adiabatic nanofocusing probes for scanning near-field optical microscopy (SNOM). Field calculations show that only the lowest order eigenmode of such a taper can reach the very apex and thus induce the generation of strongly enhanced near-field signals. Higher-order modes are coupled into the far field at finite distances from the apex. Here, we demonstrate experimentally how to distinguish and separate between the lowest and higher-order eigenmodes of such a metallic taper by filtering in the spatial frequency domain. Our approach has the potential to considerably improve the signal-to-background ratio in spectroscopic experiments at the nanoscale.

Far-field background suppression in tip-modulated apertureless near-field optical microscopy

2006 ◽  
Vol 99 (12) ◽  
pp. 124309 ◽  
Author(s):  
Pietro Giuseppe Gucciardi ◽  
Guillaume Bachelier ◽  
Maria Allegrini
Keyword(s):  
Optical Microscopy ◽  
Near Field ◽  
Background Suppression ◽  
Far Field

scholarly journals Near-Field IR Orientational Spectroscopy of Silk

2019 ◽  
Author(s):  
Meguya Ryu ◽  
Reo Honda ◽  
Aina Reich ◽  
Adrian Cernescu ◽  
Jing-Liang Li ◽  
...  
Keyword(s):  
Optical Microscopy ◽  
Spatial Resolution ◽  
Cross Sections ◽  
Molecular Orientation ◽  
Near Field ◽  
Beta Sheets ◽  
Far Field ◽  
Absorbance Measurement

Orientational dependence of the IR absorbing amide bands of silk is demonstrated from two orthogonal longitudinal and transverse microtome slices only $\sim 100$~nm thick. A scanning near-field optical microscopy (SNOM) which preferentially probes orientation perpendicular to the sample's surface was used. Spatial resolution of silk-epoxy boundary was defined with a $\sim 100$~nm resolution while the spectra were collected by a $\sim 10$~nm tip. Ratio of the absorbance of the amide-II C-N at 1512~cm$^{-1}$ and amide-I C=O $\beta$-sheets at 1628~cm$^{-1}$ showed sensitivity of SNOM to the molecular orientation. SNOM characterisation is complimentary to the far-field absorbance which is sensitive to the in-plane polarisation. Volumes with cross sections smaller than 100~nm can be characterised for molecular orientation. A method of absorbance measurements at four angles of slice cut orientation, which is equivalent to the four polarisation angles absorbance measurement is proposed.

Progress in near-field scanning optical microscopy (NSOM)

1988 ◽  
Vol 46 ◽  
pp. 436-437
Author(s):  
E. Betzig ◽  
M. Isaacson ◽  
H. Barshatzky ◽  
K. Lin ◽  
A. Lewis
Keyword(s):  
Optical Microscopy ◽  
Near Field ◽  
Visible Region ◽  
Optical Microscope ◽  
Scanning Tunneling ◽  
Far Field ◽  
Tunneling Microscopy ◽  
Scanning Optical Microscopy ◽  
Near Field Scanning ◽  
Scanning Electron

The concept of near field scanning optical microscopy was first described more than thirty years ago1 almost two decades before the validity of the technique was verified experimentally for electromagnetic radiation of 3cm wavelength.2 The extension of the method to the visible region of the spectrum took another decade since it required the development of micropositioning and aperture fabrication on a scale five orders of magnitude smaller than that used for the microwave experiments. Since initial reports on near field optical imaging8-6, there has been a growing effort by ourselves6 and other groups7 to extend the technology and develop the near field scanning optical microscope (NSOM) into a useful tool to complement conventional (i.e., far field) scanning optical microscopy (SOM), scanning electron microscopy (SEM) and scanning tunneling microscopy. In the context of this symposium on “Microscopy Without Lenses”, NSOM can be thought of as an addition to the exploding field of scanned tip microscopy although we did not originally conceive it as such.

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