2017
Autores
Santos, DF; Guerreiro, A; Baptista, JM;
Publicação
OPTIK
Abstract
We propose a refractive index sensor based on surface plasmon resonance (SPR) in a gold wire partially incrusted on the surface of a D-type fiber and in contact with the external medium for increased sensitivity and roughness. The sensor is studied using numerical simulations based on the finite element method (FEM) and is compared with a more conventional D-type fiber SPR where the wire is replaced with a gold film. The numerical work estimates the sensitivity and resolution for different analytic refractive indexes (RI) in the range of 1.30-1.40, for a sensor based on the wavelength interrogation method. The results indicate that the use of the gold wire provides a better sensitivity when compared with the gold film, while supporting multiple peaks in different wavelengths, each with distinct values of sensitivity and resolution.
2017
Autores
Silva, NA; Ferreira, TD; Costa, JC; Gomes, M; Alves, RA; Guerreiro, A;
Publicação
THIRD INTERNATIONAL CONFERENCE ON APPLICATIONS OF OPTICS AND PHOTONICS
Abstract
The realization of tabletop optical analogue experiments of superfluidity relies on the engineering of suitable optical media, with tailored optical properties. This work shows how quantum atomic optical systems can be used to develop highly tunable optical media, with localized control of both linear and nonlinear susceptibility. Introducing the hydrodynamic description of light, the superfluidity of light in these atomic media is investigated through GPU-enhanced numerical simulations, with the numeric observation of the superfluidic signature of suppressed scattering through a defect.
2017
Autores
Gomes, M; Costa, JC; Alves, RA; Silva, NA; Guerreiro, A;
Publicação
THIRD INTERNATIONAL CONFERENCE ON APPLICATIONS OF OPTICS AND PHOTONICS
Abstract
Under specific conditions, there is a formal analogy between the fundamental equations of electromagnetism and relativistic gravitation, described by the Einstein field equations of general relativity. In this paper, we report on how we have used this analogy to implement a solver of the Einstein equations adapting algorithms initially developed for electromagnetism, combined with methods of heterogeneous supercomputing, in GPU that can achieve fast computing and exhibit good performance. We also present the results of the simulations used to validate our solver. © 2017 SPIE.
2017
Autores
Costa, JC; Gomes, M; Alves, RA; Silva, NA; Guerreiro, A;
Publicação
THIRD INTERNATIONAL CONFERENCE ON APPLICATIONS OF OPTICS AND PHOTONICS
Abstract
We present a numerical implementation of a solver for the Maxwell-Bloch equations to calculate the propagation of a light pulse in a nonlinear medium composed of an atomic gas in one, two and three dimensional systems. This implementation solves the wave equation of light using a finite difference method in the time domain scheme, while the Bloch equations for the atomic population in each point of the simulation domain are integrated using splitting methods. We present numerical simulations of atomic-gas systems and performance benchmarks.
2017
Autores
Guerreiro, A; Mendonca, JT; Costa, JC; Gomes, M; Silva, NA;
Publicação
THIRD INTERNATIONAL CONFERENCE ON APPLICATIONS OF OPTICS AND PHOTONICS
Abstract
The problem of electromagnetic wave propagation in time varying media is very old, but in recent years it has been revisited at a more fundamental level leading to the introduction of several new concepts, such as Time Refraction. These concepts explore the symmetries between space and time and can be transposed to different fields by establishing powerful analogies between effects in Electrodynamics, Optics and problems in Quantum Cosmology and in what is sometimes called Analogue Gravity. We examine the alteration of the ordinary (spatial) Fresnel laws of refraction at the interface between two media when the optical properties of one of the media varies in time.
2017
Autores
Alves, RA; Silva, NA; Costa, JC; Gomes, M; Guerreiro, A;
Publicação
THIRD INTERNATIONAL CONFERENCE ON APPLICATIONS OF OPTICS AND PHOTONICS
Abstract
Localized plasmons in metallic nanostructures present strong analogies with Quantum Mechanical problems of particles trapped in potential wells. In this paper we take this analogy further using the Madelung Formalism of Quantum Mechanics to express the fluid equations describing the charge density of the conduction electrons and corresponding interaction with light in terms of an effective generalized Non-linear Schrodinger equations. Within this context, it is possible to develop the analogy of a plasmonic atom and molecule that exhibits Rabi oscillations, Stark effect, among other Quantum Mechanical effects.
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