Aperture synthesis with a monochromatic metasurface imaging system for 3D near-field imaging

We experimentally demonstrate that high-resolution terahertz focusing can be realized in planar metalenses, which consist of arrays of different V-shaped antenna units on a silicon substrate. Numerical results show that a larger numerical aperture of metalenses can provide smaller full width at half maximum of field distribution, leading to higher spatial resolution. The measurement of fabricated metalenses samples was performed by a terahertz near-field imaging system, and experimental results agree well with the numerical prediction. Especially for 1.1 THz incident light, when the numerical aperture increases from 0.79 to 0.95, the full width at half maximum correspondingly decreases from 343 μm to 206 μm, offering an improvement of spatial resolution.

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New applications of near-field optical storage

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100136660 ◽

1995 ◽

Vol 53 ◽

pp. 58-59

Author(s):

G. S. Kino ◽

S. Hayashi ◽

I. Ichimura

Keyword(s):

Refractive Index ◽

Imaging System ◽

Near Field ◽

Spot Size ◽

Optical Storage ◽

Objective Lens ◽

Near Field Imaging ◽

New Type ◽

New Applications ◽

Field Imaging

Some time ago, we described a new type of near-field imaging system using the Solid Immersion Lens. A confocal microscope using this principle has demonstrated sub-100 nm resolution with visible light. In this paper, we will describe how this device is being applied to increasing the density of optical storage in CD ROMs and magneto-optical storage systems.The SIL is placed between the objective and the disk. As illustrated in Fig. 1(a), if the SIL is in the form of a hemisphere, rays enter it along its radii and converge at its center. If the refractive index of the SIL is n, the wavelength in this material is reduced by 1/n and consequently increases the effective NA of the objective lens by the refractive index n and decreases the spot size by 1/n. With this configuration, we were able to obtain good quality images of a grating with 100 nm gaps and strip widths.

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Calibration for a Hybrid MIMO Near-field Imaging System to Mitigate Antennas Effects

2020 International Workshop on Antenna Technology (iWAT) ◽

10.1109/iwat48004.2020.1570608734 ◽

2020 ◽

Author(s):

Ha Hoang ◽

Zeeshan Ahmed ◽

Matthias John ◽

Patrick McEvoy ◽

Max Ammann

Keyword(s):

Imaging System ◽

Near Field ◽

Near Field Imaging ◽

Field Imaging

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Near-field imaging system fed by lens antenna focal plane array at sub-millimeter frequency

2014 IEEE Antennas and Propagation Society International Symposium (APSURSI) ◽

10.1109/aps.2014.6905061 ◽

2014 ◽

Cited By ~ 1

Author(s):

Erio Gandini ◽

Nuria Llombart ◽

Andrea Neto

Keyword(s):

Focal Plane ◽

Imaging System ◽

Near Field ◽

Focal Plane Array ◽

Lens Antenna ◽

Near Field Imaging ◽

Field Imaging

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UWB MST MEMS-based near-field imaging system

2008 IEEE Antennas and Propagation Society International Symposium ◽

10.1109/aps.2008.4619552 ◽

2008 ◽

Author(s):

S. Capdevila ◽

M. Jofre ◽

J. Rodriguez ◽

M. Guardiola ◽

A. Papio ◽

...

Keyword(s):

Imaging System ◽

Near Field ◽

Near Field Imaging ◽

Field Imaging

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Localization and Monitoring of People With a Near-Field Imaging System

Pervasive and Smart Technologies for Healthcare ◽

10.4018/978-1-61520-765-7.ch004 ◽

2010 ◽

pp. 78-96 ◽

Cited By ~ 1

Author(s):

Matti Linnavuo ◽

Henry Rimminen

Keyword(s):

Imaging System ◽

Near Field ◽

Fall Detection ◽

Sensor Data ◽

Near Field Imaging ◽

Vital Functions ◽

Technology Applications ◽

Posture Recognition ◽

Indoor Tracking ◽

Field Imaging

The chapter describes the state of the art and potentialities of near-field imaging (NFI) technology, applications, and nursing tools in health care. First, principles of NFI are discussed. Various uses of NFI sensor data are presented. The data can be used for indoor tracking, automatic fall detection, activity monitoring, bed exit detection, passage control, vital functions monitoring, household automation and other applications. Special attention is given to the techniques and problems in localization, posture recognition, vital functions recording and additional functions for people identification. Examples of statistical analysis of person behavior are given. Three cases of realized applications of NFI technique are discussed.

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