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Publications

Publications by Nuno Azevedo Silva

2017

Persistent currents of superfluidic light in a four-level coherent atomic medium

Authors
Silva, NA; Mendonca, JT; Guerreiro, A;

Publication
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS

Abstract
In this work, we investigate the superfluidic properties of light propagating in a four-level coherent atomic medium. The model is derived under the paraxial approximation in the form of a generalized nonlinear Schrodinger equation and features spatially controllable and quantum-enhanced optical properties, which can offer new possibilities in the field of optical analogue systems. In particular, we use this versatility to study the dynamics of an optical vortex beam confined in a nontrivial connected geometry, finding numerical evidence of another superfluidic signature analogue: the persistent current of light. (C) 2017 Optical Society of America

2017

Dissipative solitons in 4-level atomic optical systems

Authors
Silva, NA; Almeida, AL; Costa, JC; Gomes, M; Alves, RA; Guerreiro, A;

Publication
THIRD INTERNATIONAL CONFERENCE ON APPLICATIONS OF OPTICS AND PHOTONICS

Abstract
In this work we develop a theoretical model to describe the propagation of an optical pulse in a 4-level atomic system. We investigate the existence of dissipative soliton solutions and analyze the stability of these solitary waves, comparing the analytical results with computational simulations based on the effective (1+1)-dimensional model derived from the Maxwell-Bloch equation under the slowly-varying envelope approximation.

2017

Quantum wires as sensors of the electric field: A model into quantum plasmonics

Authors
Alves, RA; Costa, JC; Gomes, M; Silva, NA; Guerreiro, A;

Publication
2017 25TH INTERNATIONAL CONFERENCE ON OPTICAL FIBER SENSORS (OFS)

Abstract
This paper presents a study for a fibre optic sensor based on quantum wires to detect and measure the amplitude and direction of a static electric field. This study is supported by the analogy of the fluid equations describing the free electrons in the quantum wires and the Madelung formalism of Quantum Mechanics. In this context, it is possible to construct a diatomic plasmonic molecule whose energy levels can be Stark shifted by an external electric field and readout using a light beam tuned to the Rabi oscillations of these levels. Choosing the adequate design parameters it is possible to estimate a sensitivity of 100nm/NC-1.

2017

Doppler Broadening effects in Plasmonic Quantum Dots

Authors
Alves, RA; Silva, NA; Costa, JC; Gomes, M; Guerreiro, A;

Publication
THIRD INTERNATIONAL CONFERENCE ON APPLICATIONS OF OPTICS AND PHOTONICS

Abstract
In this paper we analyse the effects of the Doppler shift on the optical response of a nanoplasmonic system. Through the development of a simplified model based on the Hydrodynamic Drude model we analyse the response of a quantum dot embed in a moving fluid, predicting the Doppler broadening and the shift of the spectral line.

2017

Pinching optical potentials for spatial nonlinearity management in Bose-Einstein Condensates

Authors
Silva, NA; Costa, JC; Gomes, M; Alves, RA; Guerreiro, A;

Publication
THIRD INTERNATIONAL CONFERENCE ON APPLICATIONS OF OPTICS AND PHOTONICS

Abstract
Here we explore the possibility of controlling the inhomogeneities in quasi-1D Bose-Einstein condensates using a spatial variation of the transverse confinement potential and explore different optical strategies to realize these pinched traps. Furthermore, we also present some early stage results on the dynamics of matter-wave solitons in such systems using computational simulations of the full 3D Gross-Pitaevskii equation.

2017

Tunable light fluids using quantum atomic optical systems

Authors
Silva, NA; Ferreira, TD; Costa, JC; Gomes, M; Alves, RA; Guerreiro, A;

Publication
QUANTUM PHOTONIC DEVICES

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.

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