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Publications

Publications by Pedro Jorge

2012

Sensing characteristics of tapered High-Birefringent optical fiber

Authors
Layeghi, A; Zibaii, MI; Sadeghi, J; Frazao, O; Jorge, PAS; Latifi, H;

Publication
22ND INTERNATIONAL CONFERENCE ON OPTICAL FIBER SENSORS, PTS 1-3

Abstract
A high-birefringent fiber (HBF) was tapered as adiabatic in sequence steps by utilizing a CO2 laser and its birefringence was measured in fiber loop mirror (FLM) setup. The birefringence of tapered section and total sensor was obtained to be -8.02x10(-2), and 2.46x10(-4), respectively. Then, refractive index (RI) sensitivity increased and temperature sensitivity of the tapered Hi-Bi fiber (THBF) decreased. The sensitivity of the proposed FLM interferometer for RI changes in the range from 1.3380 to 1.3470 was measured to be 389.85 nm/RIU. The temperature sensitivity in the range from 50 degrees C to 90 degrees C was measured to be -1.19nm/degrees C.

2012

Temperature-independent pressure sensor using triangular-shape of Suspended-Core fiber

Authors
Zibaii, MI; Nouri, S; Sadeghi, J; Latifi, H; Jorge, PAS; Schuster, K; Kobelke, J; Frazao, O;

Publication
22ND INTERNATIONAL CONFERENCE ON OPTICAL FIBER SENSORS, PTS 1-3

Abstract
In this work, fiber in-line Mach-Zehnder Interferometer (MZI) based on triangular-shape suspended core fibers (SCFs) is investigated. The sensitivity of the sensing head was determined for pressure and temperature, respectively. The sensitivities are 0.4 pm/psi and 13 pm/psi for longitudinal and radial pressure, respectively. The sensing head was also subjected to temperature and presented very low sensitivity.

2008

Nanoparticles for Enhanced Contrast Optical Coherence Tomography

Authors
Maule, CD; Quaresma, P; Carvalho, PA; Jorge, P; Pereira, E; Rosa, CC;

Publication
1ST CANTERBURY WORKSHOP ON OPTICAL COHERENCE TOMOGRAPHY AND ADAPTIVE OPTICS

Abstract
Recently the area of bioimaging has benefited from new types of image enhancing agents such as quantum dots, carbon nanotubes and other nanoparticles. Cellular or even molecular level resolution has been achieved with different techniques during these last years (i.a. Fluorescence microscopy, PET/CT scan, AFM). Optical Coherence Tomography (OCT) as an imaging technique should also profit from newly developed probes. In this work we explored the tunable properties of different types of nanoparticles as contrast enhancers in OCT applications. We mainly studied the development and characteristics of metallic nanoparticles with tunable properties: gold nanoshells made of a silica core coated with a gold shell. Nanoshell and nanoparticles processing techniques are discussed, as well as their optimization for designing particles with specific absorption and scattering characteristics, and its use in OCT imaging.

2011

Rapid Fabrication of Dual Analyte Luminescent Optrodes by Self-Guiding Photo-Polymerization

Authors
Jorge, PAS; Maule, C; Soppera, O; Marques, PVS;

Publication
IEEE PHOTONICS TECHNOLOGY LETTERS

Abstract
A technique for the fabrication of luminescence-based fiber-optic optrodes with multiple analyte sensitivity is proposed. Combination of photosensitive polymers doped with different luminescent indicators enabled the production of fiber probes, by self-guiding photo-polymerization, with different geometries and sensing capabilities. Results demonstrating the method flexibility are shown with luminescent probes doped with CdSe/ZnS quantum dots and an organometalic ruthenium complex for simultaneous detection of oxygen and temperature.

2009

Optical Fibre Sensing and Analytical Imaging with Semiconductor Nanocrystals

Authors
Jorge, PAS; Maule, C; Rodrigues, H; Esteves da Silva, JCGE; Farahi, F;

Publication
ICTON: 2009 11TH INTERNATIONAL CONFERENCE ON TRANSPARENT OPTICAL NETWORKS, VOLS 1 AND 2

Abstract
Semiconductor nanocrystals have unique optical properties that make them promising alternatives to traditional dyes in many luminescence based analytical techniques. An overview of the more relevant progresses in the application of quantum dots (QDs) as analytical probes in optical fibre sensing and imaging application will be addressed. Experimental results regarding the use of QDs as self-referenced multiplexed probes for chemical sensing and analytical imaging will be presented.

2010

Luminol-Doped Nanostructured Composite Materials for Chemiluminescent Sensing of Hydrogen Peroxide

Authors
Duarte, AJ; Rocha, C; Silveira, F; Aguilar, GG; Jorge, PAS; Leitao, JMM; Algarra, M; Esteves da Silva, JCGE;

Publication
ANALYTICAL LETTERS

Abstract
Silica based nanostructured composite materials doped with luminol and cobalt(II) ion were synthesized and characterized, resulting in a highly chemiluminescent material in the presence of hydrogen peroxide. A detection system with the CL light guided from the reaction tube to the photomultiplier tube using a one millimeter glass optical fiber was developed and assessed. A linear response was observed using a semi-logarithm calibration between 50-2000M hydrogen peroxide with 1M as the limit of detection.

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