Терагерцовый микроскоп на основе эффекта твердотельной иммерсии для визуализации биологических тканей-=SUP=-*-=/SUP=-

A novel method of terahertz (THz) microscopy was proposed for imaging of biological tissues with sub-wavelength spatial resolution. It allows for overcoming the Abbe diffraction limit and provides a sub-wavelength resolution thanks to the solid immersion effect – i.e. to the reduction in the dimensions of electromagnetic beam caustic, when the beam is focused in free space, at a small distance (smaller than the wavelength) behind the medium featuring high refractive index. An experimental setup realizing the proposed method was developed. It uses a backward wave oscillator, as a THz-wave emitter, and a Golay cell, as a THz-wave detector. In this setup, the radiation is focused behind the silicon hemisphere in order to realize the solid immersion effect. The spatial resolution of 0.15λ was demonstrated for the developed microscope, while the measurements were carried out at the wavelength of λ=500 μm, with the metal-air interface as a test object. Such a high spatial resolution represents a significant advantage over that of the previously reported arrangements of solid immersion microscopes. The solid immersion microscopy does not imply using any diaphragms or other near-field probes for achieving the sub-wavelength spatial resolution; thus, it eliminates the energy losses associated with such elements. The proposed methods were applied for imaging of biological tissues, and the observed results highlight its potential in biology and medicine.

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Photoreflectance Near-Field Scanning Optical Microscopy

MRS Proceedings ◽

10.1557/proc-588-13 ◽

1999 ◽

Vol 588 ◽

Cited By ~ 1

Author(s):

Charles Paulson ◽

Brian Hawkins ◽

Jingxi Sun ◽

Arthur B. Ellis ◽

Leon Mccaughan ◽

...

Keyword(s):

Optical Microscopy ◽

Electric Fields ◽

Spatial Resolution ◽

High Intensity ◽

Near Field ◽

And Topology ◽

Wavelength Resolution ◽

Scanning Optical Microscopy ◽

Near Field Scanning ◽

Sub Wavelength

AbstractA novel Near-field Scanning Optical Microscopy (NSOM) technique is used to obtain simultaneous topology, photoluminescence and photoreflectance (PR) spectra. PR spectra from GaAs surfaces were obtained and the local electric fields were calculated. Sub-wavelength resolution is expected for this technique and achieved for PL and topology measurements. Photovoltages, resulting from the high intensity of light at the NSOM tip, can limit the spatial resolution of the electric field determination.

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Development of a Combined Scanning Ion-Conductance and Nearfield Optical Microscope to Image Living Cells

Microscopy and Microanalysis ◽

10.1017/s1431927600018201 ◽

1999 ◽

Vol 5 (S2) ◽

pp. 976-977

Author(s):

M. Raval ◽

D. Klenerman ◽

T. Rayment ◽

Y. Korchev ◽

M. Lab

Keyword(s):

Optical Microscopy ◽

Biological Samples ◽

Near Field ◽

Sample Surface ◽

Optical Microscope ◽

Ion Conductance ◽

Simultaneous Generation ◽

Simple Arrangement ◽

Wavelength Resolution ◽

Sub Wavelength

It is important to be able to image biological samples in a manner that is non-invasive and allows the sample to retain its functionality during imaging.A member of the SPM (scanning probe microscopy) family, SNOM (scanning near-field optical microscopy), has emerged as a technique that allows optical and topographic imaging of biological samples whilst satisfying the above stated criteria. The basic operating principle of SNOM is as follows. Light is coupled down a fibre-optic probe with an output aperture of sub-wavelength dimensions. The probe is then scanned over the sample surface from a distance that is approximately equal to the size of its aperture. By this apparently simple arrangement, the diffraction limit posed by conventional optical microscopy is overcome and simultaneous generation of optical and topographic images of sub-wavelength resolution is made possible. Spatial resolution values of lOOnm in air and 60nm in liquid[1,2] are achievable with SNOM.

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Study of Hot Spots Probing Based on Meta-Pillars Array

Journal of Computational and Theoretical Nanoscience ◽

10.1166/jctn.2019.8483 ◽

2019 ◽

Vol 16 (9) ◽

pp. 3692-3697

Author(s):

Yisha You ◽

Fujuan Huang ◽

Yongqi Fu ◽

Shaoli Zhu

Keyword(s):

Hot Spots ◽

Near Field ◽

Optical Microscope ◽

Microscopic Imaging ◽

Secondary Sources ◽

Imaging Application ◽

Calculation Results ◽

Wavelength Resolution ◽

Near Field Scanning ◽

Sub Wavelength

Inspired by imaging principle of near-field scanning optical microscope (NSOM), meta-pillars array is designed and analyzed on the basis of microscopic imaging application with high resolution. Finely focused spots acting as tiny secondary sources for illumination at near-field can be derived under supporting of the meta-pillars for the purpose of increasing imaging resolution. Numerical calculation is carried out on the basis of finite difference and time domain (FDTD) algorithm. Our calculation results demonstrate that the meta-pillars are capable of supporting the microscopic imaging at sub-wavelength resolution.

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Enhancement of Optical Transmission Through Planar Nano-Apertures in a Metal Film

Electronic and Photonic Packaging, Electrical Systems and Photonic Design, and Nanotechnology ◽

10.1115/imece2003-55235 ◽

2003 ◽

Cited By ~ 1

Author(s):

Eric X. Jin ◽

Xianfan Xu

Keyword(s):

Metal Film ◽

Incident Light ◽

Near Field ◽

Transmission Efficiency ◽

Localized Surface Plasmon ◽

Fabry Perot ◽

Wavelength Resolution ◽

Signal Contrast ◽

Negative Role ◽

Sub Wavelength

In this work, we investigate transmission enhancement through ridged-apertures of nanometer size in a metal film in the optical frequency range. It is demonstrated that the fundamental propagation TE10 mode concentrated in the gap between the two ridges of the aperture provides transmission efficiency higher than unity, and the size of the gap between the two ridges determines the sub-wavelength resolution. Fabry-Perot-like resonance with respect to the thickness of the aperture and the red-shift phenomena with respect to the wavelength of the incident light are observed. As a comparison, transmission through regular apertures is also computed, and is found much lower. Localized surface plasmon (LSP) is excited on the edges of the aperture in a silver film but plays a negative role with respect to the field concentration and signal contrast. With optimized geometries, the ridged apertures are capable of achieving sub-wavelength resolution in the near field with transmission efficiency above unity and high contrast.

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Fast IR imaging with sub-wavelength resolution using a transient near-field probe (tipless near-field microscopy)

10.1117/12.347580 ◽

1999 ◽

Author(s):

Daniel V. Palanker ◽

Todd I. Smith ◽

H. Alan Schwettman

Keyword(s):

Near Field ◽

Ir Imaging ◽

Wavelength Resolution ◽

Sub Wavelength

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Polariton-enhanced near field lithography and imaging with infrared light

MRS Proceedings ◽

10.1557/proc-820-r1.2 ◽

2004 ◽

Vol 820 ◽

Cited By ~ 8

Author(s):

Gennady Shvets ◽

Yaroslav A. Urzhumov

Keyword(s):

Near Field ◽

Resolution Enhancement ◽

Field Measurements ◽

Index Of Refraction ◽

Infrared Light ◽

Ir Radiation ◽

Novel Approach ◽

Wavelength Resolution ◽

Near Field Effect ◽

Sub Wavelength

AbstractA novel approach to making a material with negative index of refraction in the infrared frequency band is described. Materials with negative dielectric permittivity ε are utilized in this approach. Those could be either plasmonic (metals) or polaritonic (semiconductors) in nature. A sub-wavelength plasmonic crystal (SPC), with the period much smaller than the wavelength of light, consisting of nearly-touching metallic cylinders is shown to support waves with negative group velocity. The usage of such waves for sub-wavelength resolution imaging is demonstrated in a numerical double-slit experiment. Another application of the negative-epsilon materials is laser-driven near field nanolithography. Any plasmonic or polaritonic material with nega- tive ε = –εd sandwiched between dielectric layers with εd > 0 can be used to significantly decrease the feature size. It is shown that a thin slab of SiC is capable of focusing the mid- IR radiation of a CO2 laser to several hundred nanometers, thus paving the way for a new nano-lithographic technique: Phonon Enhanced Near Field Lithography in Infrared (PENFIL). Although an essentially near-field effect, this resolution enhancement can be quantified using far-field measurements. Numerical simulations supporting such experiments are presented.

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