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Publications

2018

Superfluidity of light in nematic liquid crystals

Authors
Ferreira, TD; Silva, NA; Guerreiro, A;

Publication
Physical Review A

Abstract
Optical analog experiments have captured a lot of interest in recent years by offering a strategy to test theoretical models and concepts that would be otherwise untestable. The approach relies on the similarity between the mathematical model for light propagation in nonlinear optical media and the model to be mimicked. In particular, the analogy between light and a quantum fluid with superfluidlike properties has been studied extensively. Still, while most of these studies use thermo-optical media to perform these experiments, the possibility of using nematic liquid crystals to perform such optical analog experiments remains to be analyzed. This work explores how this medium can constitute an alternative to materials more commonly used in optical analogs, such as thermo-optical media, and how its tunable properties can be advantageous to explore and better control fluidlike properties of light. Moreover, we explore the analogy between the propagation of light and a quantum fluid, and propose a pump-probe experiment to measure the dispersion relation of the superfluid analog. © 2018 American Physical Society.

2017

2D computational modeling of optical trapping effects on malaria-infected red blood cells

Authors
Paiva, JS; Ribeiro, RSR; Jorge, PAS; Rosa, CC; Guerreiro, A; Cunha, JPS;

Publication
Optics InfoBase Conference Papers

Abstract
A computational method for optical fiber trapping of healthy and Malariainfected blood cells characterization is proposed. A trapping force relation with the infection stage was found, which could trigger the development of a diagnostic sensor. © OSA 2017.

2017

Optimization of modal sensitivity in nanowire SPR multimode sensor

Authors
Santos, DF; Guerreiro, A; Baptista, JM;

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

Abstract
This paper presents a multimode fiber sensor that uses surface plasmon resonance on a metallic wire to measure refractive index. Numerical simulations based on the finite element method reveal the sensor supports several plasmon modes in the wire capable of coupling with the multiples optical fiber modes. Therefore, the sensor configuration creates multiple resonances at different wavelengths, with different values of the loss, sensitivity, among other parameters. Choosing the appropriate mode and filtering out the rest of the modes allows to optimize the sensor performance. In the present work a sensitivity of 5340nm/RIU and resolution of 1.87x10(-6) RIU were found.

2017

SPR optimization using metamaterials in a D-type PCF refractive index sensor

Authors
Santos, DF; Guerreiro, A; Baptista, JM;

Publication
OPTICAL FIBER TECHNOLOGY

Abstract
Using the finite element method (FEM), this paper presents a numerical investigation of the performance analysis of a D-type photonic crystal fiber (D-type PCF) for refractive index sensing, based on surface plasmon resonance (SPR) with a planar structure made out of a metamaterial. COMSOL Multiphysics was used to evaluate the design of the referred refractive index optical fiber sensor, with higher accuracy and considerable economy of time and resources. A study of different metamaterials concentrations conformed by aluminum oxide (Al2O3) and silver (Ag) is carried out. Another structural parameters, which influences the refractive index sensor performance, the thickness of the metamaterial, is also investigated. The results indicate that the use of metamaterials provides a way of improving the performance of SPR sensors on optical fibers and allows to tailor the working parameters of the sensor.

2017

Surface plasmon resonance sensor based on D-type fiber with a gold wire

Authors
Santos, DF; Guerreiro, A; Baptista, JM;

Publication
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 Elsevier GmbH

Supervised
thesis

2017

Optical fiber tools for single cell trapping and manipulation

Author
Ana Rita da Silva Rodrigues Ribeiro

Institution
UP-FCUP

2017

Research project: Heterogeneous Supercomputation for Non-equilibrium Mesoscale Optics

Author
Nuno Miguel Azevedo Silva

Institution
UP-FCUP

2017

Development of a solver of the Maxwell-Bloch equations with GPGPUs

Author
João Paulo Couto Costa

Institution
UP-FCUP

2017

Development of a simulator of light-matter interaction using GPGPU: from plasmas to atomic gases

Author
Miguel Boaventura Teixeira Gomes

Institution
UP-FCUP

2017

Nano-Plasmonics: a stepping stone into Non-linear Quantum Plasmonics

Author
Rúben Azinheira Alves

Institution
UP-FCUP