Sensitivity enhancement of plasmonic grating in near field

AbstractStructured illumination microscopy (SIM) is a well-established fluorescence imaging technique, which can increase spatial resolution by up to a factor of two. This article reports on a new way to extend the capabilities of structured illumination microscopy, by combining ideas from the fields of illumination engineering and nanophotonics. In this technique, plasmonic arrays of hexagonal symmetry are illuminated by two obliquely incident beams originating from a single laser. The resulting interference between the light grating and plasmonic grating creates a wide range of spatial frequencies above the microscope passband, while still preserving the spatial frequencies of regular SIM. To systematically investigate this technique and to contrast it with regular SIM and localized plasmon SIM, we implement a rigorous simulation procedure, which simulates the near-field illumination of the plasmonic grating and uses it in the subsequent forward imaging model. The inverse problem, of obtaining a super-resolution (SR) image from multiple low-resolution images, is solved using a numerical reconstruction algorithm while the obtained resolution is quantitatively assessed. The results point at the possibility of resolution enhancements beyond regular SIM, which rapidly vanishes with the height above the grating. In an initial experimental realization, the existence of the expected spatial frequencies is shown and the performance of compatible reconstruction approaches is compared. Finally, we discuss the obstacles of experimental implementations that would need to be overcome for artifact-free SR imaging.

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Structural symmetry breaking induced polarization sensitivity enhancement: Used for THz tri-band mechanical tunability

Modern Physics Letters B ◽

10.1142/s0217984919500325 ◽

2019 ◽

Vol 33 (05) ◽

pp. 1950032

Author(s):

Qi Rong ◽

Fangrong Hu ◽

Yuanyuan Li ◽

Shan Yin ◽

Mingzhu Jiang ◽

...

Keyword(s):

Modulation Depth ◽

Near Field ◽

Sensitivity Enhancement ◽

Electromagnetic Response ◽

Integration Time ◽

Polarization Sensitivity ◽

Thz Wave ◽

Field Coupling ◽

Mechanical Tunability ◽

Novel Design

A symmetry broken hexagram metamaterial (SBHM) is presented to enhance the polarization sensitivity, and thus realize mechanically controlling the transmissions of tri-band in terahertz (THz) region. This SBHM has different electromagnetic response for rotating clockwise and anticlockwise, respectively. When incident THz wave is polarized in the direction of [Formula: see text], the SBHM has three stopbands with central frequencies at 0.36 THz, 0.52 THz and 0.75 THz, respectively. When the SBHM rotates clockwise [Formula: see text], the transmission of 0.52 THz increases from 0.17 to 0.85, and its modulation depth reaches 68%. On the contrary, when it rotates anticlockwise [Formula: see text], the transmissions of the other two bands can be modulated simultaneously, and their modulation depth are 78% and 40%, respectively. The physical mechanism for the tunability is investigated using finite-integration time-domain (FITD) method. The results indicated that the tri-band tunability in the SBHM is due to the mode transfer and polarization sensitivity enhancement which is induced by near field coupling. This novel design proves a new way for modulation, selection and switching of the THz wave at multiband.

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Sensitivity Enhancement in Near-Field Photothermal-Lens Detection in Capillary Electrophoresis Using Laser-Induced Online Precipitation

Applied Spectroscopy ◽

10.1366/10-06151 ◽

2011 ◽

Vol 65 (11) ◽

pp. 1275-1280 ◽

Cited By ~ 3

Author(s):

Dmitry A. Nedosekin ◽

Werner Faubel ◽

Mikhail A. Proskurnin ◽

Ute Pyell

Keyword(s):

Capillary Electrophoresis ◽

Near Field ◽

Sensitivity Enhancement

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Sensitivity enhancement of integrated optical near field sensors

10.1117/12.780006 ◽

2008 ◽

Author(s):

Julia Hahn ◽

Frank Fecher ◽

Juergen Petter ◽

Theo Tschudi

Keyword(s):

Near Field ◽

Sensitivity Enhancement ◽

Integrated Optical

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Sensitivity enhancement of plasmonic grating in the local field

Optics Express ◽

10.1364/oe.400382 ◽

2020 ◽

Vol 28 (18) ◽

pp. 26143

Author(s):

L. L. Frumin ◽

D. A. Shapiro

Keyword(s):

Local Field ◽

Sensitivity Enhancement ◽

Plasmonic Grating

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Near-field scanning optical microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100144644 ◽

1986 ◽

Vol 44 ◽

pp. 642-643

Author(s):

E. Betzig ◽

A. Harootunian ◽

M. Isaacson ◽

A. Lewis

Keyword(s):

Near Field ◽

Optical Microscope ◽

Visible Radiation ◽

Field Methods ◽

Optical Elements ◽

Optical Region ◽

Order Of Magnitude ◽

Nondestructive Imaging ◽

Scanning Optical Microscopy ◽

Near Field Scanning

In general, conventional methods of optical imaging are limited in spatial resolution by either the wavelength of the radiation used or by the aberrations of the optical elements. This is true whether one uses a scanning probe or a fixed beam method. The reason for the wavelength limit of resolution is due to the far field methods of producing or detecting the radiation. If one resorts to restricting our probes to the near field optical region, then the possibility exists of obtaining spatial resolutions more than an order of magnitude smaller than the optical wavelength of the radiation used. In this paper, we will describe the principles underlying such "near field" imaging and present some preliminary results from a near field scanning optical microscope (NS0M) that uses visible radiation and is capable of resolutions comparable to an SEM. The advantage of such a technique is the possibility of completely nondestructive imaging in air at spatial resolutions of about 50nm.

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