Near and far field
About: Near and far field is a(n) research topic. Over the lifetime, 15922 publication(s) have been published within this topic receiving 220571 citation(s).
Papers published on a yearly basis
TL;DR: This work shows how electromagnetic fields can be redirected at will and proposes a design strategy that has relevance to exotic lens design and to the cloaking of objects from electromagnetic fields.
Abstract: Using the freedom of design that metamaterials provide, we show how electromagnetic fields can be redirected at will and propose a design strategy. The conserved fields-electric displacement field D, magnetic induction field B, and Poynting vector B-are all displaced in a consistent manner. A simple illustration is given of the cloaking of a proscribed volume of space to exclude completely all electromagnetic fields. Our work has relevance to exotic lens design and to the cloaking of objects from electromagnetic fields.
01 Jan 1969
TL;DR: Experimental demonstration of the optical hyperlens for sub-diffraction-limited imaging in the far field and opens up possibilities in applications such as real-time biomolecular imaging and nanolithography.
Abstract: The diffraction limit of light, which is causd by the loss of evanescent waves in the far field that carry high spatial frequency information, limits the resolution of optical lenses to the order of the wavelength of light. We report experimental demonstration of the optical hyperlens for sub-diffraction-limited imaging in the far field. The device magnifies subwavelength objects by transforming the scattered evanescent waves into propagating waves in an anisotropic medium and projects the high-resolution image at far field. The optical hyperlens opens up possibilities in applications such as real-time biomolecular imaging and nanolithography.
01 Oct 2001-Advanced Materials
TL;DR: In this paper, a point dipole analysis predicts group velocities of energy transport that exceed 0.1c along straight arrays and shows that energy transmission and switching through chain networks such as corners and tee structures is possible at high efficiencies.
Abstract: The further integration of optical devices will require the fabrication of waveguides for electromagnetic energy below the diffraction limit of light. We investigate the possibility of using arrays of closely spaced metal nanoparticles for this purpose. Coupling between adjacent particles sets up coupled plasmon modes that give rise to coherent propagation of energy along the array. A point dipole analysis predicts group velocities of energy transport that exceed 0.1c along straight arrays and shows that energy transmission and switching through chain networks such as corners (see Figure) and tee structures is possible at high efficiencies. Radiation losses into the far field are expected to be negligible due to the near-field nature of the coupling, and resistive heating leads to transmission losses of about 6 dB/lm for gold and silver particles. We analyze macroscopic analogues operating in the microwave regime consisting of closely spaced metal rods by experiments and full field electrodynamic simulations. The guiding structures show a high confinement of the electromagnetic energy and allow for highly variable geometries and switching. Also, we have fabricated gold nanoparticle arrays using electron beam lithography and atomic force microscopy manipulation. These plasmon waveguides and switches could be the smallest devices with optical functionality.
01 Nov 1964
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