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Publicações

Publicações por Pedro Jorge

2015

Optical Fiber Tweezers Fabricated by Guided Wave Photo-Polymerization

Autores
Ribeiro, RSR; Queiros, R; Soppera, O; Guerreiro, A; Jorge, PAS;

Publicação
PHOTONICS

Abstract
In this work the use of guided wave photo-polymerization for the fabrication of novel polymeric micro tips for optical trapping is demonstrated. It is shown that the selective excitation of linear polarized modes, during the fabrication process, has a direct impact on the shape of the resulting micro structures. Tips are fabricated with modes LP02 and LP21 and their shapes and output intensity distribution are compared. The application of the micro structures as optical tweezers is demonstrated with the manipulation of yeast cells.

2016

Optical fibers as beam shapers: from Gaussian beams to optical vortices

Autores
Rodrigues Ribeiro, RSR; Dahal, P; Guerreiro, A; Jorge, P; Viegas, J;

Publicação
OPTICS LETTERS

Abstract
This Letter reports a new method for the generation of optical vortices using a micropatterned optical fiber tip. Here, a spiral phase plate (2 pi phase shift) is micromachined on the tip of an optical fiber using a focused ion beam. This is a high resolution method that allows milling the fibers with nanoscale resolution. The plate acts as a beam tailoring system, transforming the fundamental guided mode, specifically a Gaussian mode, into the Laguerre-Gaussian mode (LG(01)), which carries orbital angular momentum. The experimental results are supported by computational simulations based on the finite-difference time-domain method. (C) 2016 Optical Society of America

2015

Passive interferometric interrogation of a magnetic field sensor using an erbium doped fiber optic laser with magnetostrictive transducer

Autores
Nascimento, IM; Baptista, JM; Jorge, PAS; Cruz, JL; Andres, MV;

Publicação
SENSORS AND ACTUATORS A-PHYSICAL

Abstract
An erbium doped (Er3+) fiber optic laser is proposed for magnetic field measurement. A pair of FBGs glued onto a magnetostrictive material (Terfenol-D rod) modulates the laser wavelength operation when subject to a static or a time dependent magnetic field. A passive interferometer is employed to measure the laser wavelength changes due to the applied magnetic field. A data acquisition hardware and a Lab VIEW software measure three phase-shifted signals at the output coupler of the interferometer and process them using two distinct demodulation algorithms. Results show that sensitivity to varying magnetic fields can be tuned by introducing a biasing magnetic field. A maximum error of 0.79% was found, for magnetic fields higher than 2.26 mT(RMS).

2015

Polymeric Optical Fiber Tweezers as a tool for single cell micro manipulation and sensing

Autores
Rodrigues Ribeiro, RSR; Soppera, O; Guerreiro, A; Jorge, PAS;

Publicação
24TH INTERNATIONAL CONFERENCE ON OPTICAL FIBRE SENSORS

Abstract
In this paper a new type of polymeric fiber optic tweezers for single cell manipulation is reported. The optical trapping of a yeast cell using a polymeric micro lens fabricated by guided photo polymerization at the fiber tip is demonstrated. The 2D trapping of the yeast cells is analyzed and maximum optical forces on the pN range are calculated. The experimental results are supported by computational simulations using a FDTD method. Moreover, new insights on the potential for simultaneous sensing and optical trapping, are presented.

2014

TEC4SEA-A Modular Platform for Research, Test and Validation of Technologies Supporting a Sustainable Blue Economy

Autores
Monica, P; Martins, A; Olivier, A; Matos, A; Almeida, JM; Cruz, N; Alves, JC; Salgado, H; Pessoa, L; Jorge, P; Campos, R; Ricardo, M; Pinho, C; Silva, A; Jesus, S; Silva, E;

Publicação
2014 OCEANS - ST. JOHN'S

Abstract
This paper presents the TEC4SEA research infrastructure created in Portugal to support research, development, and validation of marine technologies. It is a multidisciplinary open platform, capable of supporting research, development, and test of marine robotics, telecommunications, and sensing technologies for monitoring and operating in the ocean environment. Due to the installed research facilities and its privileged geographic location, it allows fast access to deep sea, and can support multidisciplinary research, enabling full validation and evaluation of technological solutions designed for the ocean environment. It is a vertically integrated infrastructure, in the sense that it possesses a set of skills and resources which range from pure conceptual research to field deployment missions, with strong industrial and logistic capacities in the middle tier of prototype production. TEC4SEA is open to the entire scientific and enterprise community, with a free access policy for researchers affiliated with the research units that ensure its maintenance and sustainability. The paper describes the infrastructure in detail, and discusses associated research programs, providing a strategic vision for deep sea research initiatives, within the context of both the Portuguese National Ocean Strategy and European Strategy frameworks.

2015

The efficiency of fiber optical tweezers for cell manipulation using distinct fabrication methods

Autores
Ribeiro, RSR; Soppera, O; Viegas, J; Guerreiro, A; Jorge, PAS;

Publicação
COMPLEX LIGHT AND OPTICAL FORCES IX

Abstract
In this work, the trapping efficiency of new fiber optical tweezers structures fabricated using photo polymerization and focused ion beam milling techniques is evaluated. The first fabrication methods may present limited capabilities on the tailoring of the structures, and therefore limited operation features. On the other hand, with focused ion beam milling a vast myriad of structures may be accurately fabricated, and contrarily to conventional fabrication methods, more specialized manipulation tools can be developed. In this regard, the performance of FOT for the trapping of yeast cells using spherical lenses (photo polymerization) and spiral phase lenses (FIB) will be presented. In addition, finite difference time domain (FDTD) simulations of the full vectorial optical propagation through the designed structures and the corresponding calculation of the optical forces are presented and different designs are evaluated.

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