Conductivity Mapping in Graphene through Scattering-Type Scanning Near-Field Optical Microscopy in the Mid-Infrared and Terahertz Spectral Region with 25nm Spatial Resolution

2018 ◽  
Keyword(s):  
Optical Microscopy ◽  
Spatial Resolution ◽  
Spectral Region ◽  
Near Field ◽  
Mid Infrared

Spectral-Type Probe with λ/40 Resolution for Near-Field Optical Microscopy Systems

2013 ◽  
Vol 677 ◽  
pp. 373-378
Author(s):  
Yuri N. Kulchin ◽  
Oleg B. Vitrik ◽  
Aleksandr A. Kuchmizhak
Keyword(s):  
Optical Microscopy ◽  
Light Source ◽  
Spatial Resolution ◽  
Spectral Type ◽  
Near Field ◽  
Fabrication Process ◽  
Fabry Perot ◽  
Evanescent Light

We studied numerically and experimentally the ability to develop a new probe based on fiber Fabry-Perot interferometer with an evanescent light source protruding directly toward the sample. It was shown that such probe provides a spatial resolution of no worse than ~λ/40 for λ=1550 nm. The fabrication process of the probe is described in detail.

Tapping Mode Near-Field Scanning Optical Microscopy of Molecular Crystals and Thin Films

1999 ◽  
Vol 5 (S2) ◽  
pp. 994-995
Author(s):  
C. Daniel Frisbie ◽  
Andrey Kosterin ◽  
Helena Stadniychuk
Keyword(s):  
Optical Microscopy ◽  
Spatial Resolution ◽  
Laser Light ◽  
Near Field ◽  
Sample Surface ◽  
Reflected Light ◽  
Surface Laser ◽  
Scanning Optical Microscopy ◽  
Diffraction Effects ◽  
Near Field Scanning

The diffraction of visible light limits the spatial resolution in conventional optical microscopy to about 200-300 nm. In near-field scanning optical microscopy (NSOM), resolution is improved by bringing the light source, such as the end of an optical fiber, very close to the sample surface. Laser light coupled into the opposite end of the fiber propagates down the fiber core and is emitted from the aperture of the tip. When the sample is in the near-field(roughly within one tip diameter of the end of the tip), the spatial resolution is essentially equal to the diameter of the aperture at the end of the tip and is not determined by diffraction effects. Two-dimensional imaging is accomplished by raster-scanning the sample underneath the fiber tip and collecting transmitted or reflected light at a photodetector.

Photoreflectance Near-Field Scanning Optical Microscopy

1999 ◽  
Vol 588 ◽  
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.

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.

Surface photoelectrochemistry using near-field scanning optical microscopy (NSOM)

1996 ◽  
Vol 54 ◽  
pp. 858-859
Author(s):  
Patrick J. Moyer
Keyword(s):  
Optical Microscopy ◽  
Spatial Resolution ◽  
Shear Force ◽  
Force Feedback ◽  
Near Field ◽  
Feedback Mechanism ◽  
Frequency Spectra ◽  
Water Resonance ◽  
Scanning Optical Microscopy ◽  
Near Field Scanning

Near-field scanning optical microscopy (NSOM) has been used to characterize and modify surfaces with lateral spatial resolution as high as 50 nm. Some of these experiments were performed under electrochemical conditions. Progress towards this goal involved several important steps. They include proving adequate operation of the shear force feedback mechanism in liquids and fabrication of appropriate NSOM fiber probes.With regards to shear force feedback, which is used to maintain the fiber probe within the near field of the sample, there has been ample discussion regarding the physics of the tip-sample interaction. It is important for biological and photoelectrochemical applications that the feedback mechanism operates successfully in liquid environments. Our results indicate that shear force operation in water allows for high spatial resolution NSOM characterization while providing high force sensitivity. When comparing the frequency spectra of the probe resonances in air and water, the water resonance is broadened. The broadened resonance peak when completely immersing the probe in water indicates an increase in damping.

scholarly journals Near-Field IR Orientational Spectroscopy of Silk

2019 ◽  
Vol 9 (19) ◽  
pp. 3991 ◽  
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 ◽  
Far Field ◽  
Absorbance Measurement ◽  
Β Sheets

Orientational dependence of the IR absorbing amide bands of silk is demonstrated from two orthogonal longitudinal and transverse microtome slices with a thickness of only ∼100 nm. Scanning near-field optical microscopy (SNOM) which preferentially probes orientation perpendicular to the sample’s surface was used. Spatial resolution of the silk–epoxy boundary was ∼100 nm resolution, while the spectra were collected by a ∼10 nm tip. Ratio of the absorbance of the amide-II C-N at 1512 cm − 1 and amide-I C=O β -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 the slice cut orientation, which is equivalent to the four polarisation angles absorbance measurement, is proposed.

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