Journal ArticleDOI
Near Field Focusing Using Phase Conjugating Impedance Loaded Wire Lens
TLDR
In this article, the phase conjugated energy and inductive loading of the constituent lens wire elements is shown to be essential for sub-wavelength focusing since this leads to the creation of a phase-conjugated near field predominantly determined by a convolution of the array current distribution with the real part of the Greens function which oscillates at a subwavelength scale.Abstract:
The properties of a lumped loaded wire array as a means for near field focusing using phase conjugation is studied. The constructive role of phase conjugation in the near field image formation is justified both analytically and numerically. The generation of phase conjugated energy and how this is influenced by lumped impedance loading of the wires constituting the lens is discussed. In particular it is shown that inductive loading of the constituent lens wire elements is essential for subwavelength focusing since this leads to the creation of a phase conjugated near field predominantly determined by a convolution of the array current distribution with the real part of the Greens function which oscillates at a subwavelength scale. The characteristic resolution of the lens in terms of the full width at half maximum is shown to be ~ λ/7 for a single source and better than λ/4 for two dipole sources at λ/10 source-lens separation distance.read more
Citations
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Journal ArticleDOI
Subwavelength imaging using phase-conjugating nonlinear nanoantenna arrays.
Pai-Yen Chen,Andrea Alù +1 more
TL;DR: Pairing two nonlinear metasurfaces formed by plasmonic nanoantennas loaded with χ(3) nonlinear elements put forward a realistic design for a time-reversal 'perfect lens', which can overcome the limitations in resolution and sensitivity to losses typical of negative-index lenses.
Journal ArticleDOI
Theory, Modeling and Features of Optical Nanoantennas
Andrea Alù,Nader Engheta +1 more
TL;DR: In this paper, a review of optical antenna theory, design and applications is presented, highlighting how the optical nanocircuit paradigm may be applied to achieve optical impedance matching, loading and tuning in the optical domain.
Posted Content
Far-field Imaging beyond the Diffraction Limit Using a Single Radar
TL;DR: In this article, a single radar system consisting of a spatial-temporal resonant aperture antenna (referred to as the slavery antenna) and a broadband horn antenna (termed the master antenna) is proposed.
Journal ArticleDOI
Enhanced Second-Harmonic Generation by Metasurface Nanomixer and Nanocavity
Pai-Yen Chen,Pai-Yen Chen,Christos Argyropoulos,Christos Argyropoulos,Giuseppe D'Aguanno,Andrea Alù +5 more
TL;DR: In this paper, the authors discuss the possibility of enhancing the nonlinear second-harmonic generation (SHG) from χ(2) nonlinear materials using metasurfaces consisting of suitably engineered optical nanoantenna arrays.
References
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Journal ArticleDOI
Time reversal of ultrasonic fields. I. Basic principles
TL;DR: Pulsed wave time-reversal focusing is shown using reciprocity valid in inhomogeneous medium to be optimal in the sense that it realizes the spatial-temporal matched filter to the inhomogeneity propagation transfer function between the array and the target.
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Theory of electromagnetic waves
Abstract: Spend your few moment to read a book even only few pages. Reading book is not obligation and force for everybody. When you don't want to read, you can get punishment from the publisher. Read a book becomes a choice of your different characteristics. Many people with reading habit will always be enjoyable to read, or on the contrary. For some reasons, this theory of electromagnetic waves tends to be the representative book in this website.
Journal ArticleDOI
Phase conjugation and perfect lensing
TL;DR: In this paper, the concept of the perfect lens was revisited and the possibility to achieve optical resolution well below the wavelength limit using a backward wave (also called Veselago or double-negative) material slab lens was investigated.