2004
Autores
Romero, R; Frazao, O; Pereira, DA; Salgado, HM; Araujo, FM; Ferreira, LA;
Publicação
SECOND EUROPEAN WORKSHOP ON OPTICAL FIBRE SENSORS: PROCEEDINGS
Abstract
An intensity-referenced temperature-independent curvature measurement technique using a smart composite comprising two chirped fiber Bragg gratings is demonstrated. The two gratings are embedded on opposite sides of a composite laminate and act simultaneously as curvature sensors and as wavelength discriminators, enabling an unambiguous measurement of the composite radius of curvature.
2004
Autores
Frazao, O; Rego, G; Araujo, FM; Ferreira, LA; Salgado, HM; Santos, JL;
Publicação
SECOND EUROPEAN WORKSHOP ON OPTICAL FIBRE SENSORS: PROCEEDINGS
Abstract
A new sensing configuration is proposed for simultaneous measurement of strain and temperature that relies on a single long period grating written by the electric arc technique. The underlying principle is the azimuthal asymmetry induced by the electric arc fabrication technique, which results in a device with polarization dependent insertion loss sensitive to both temperature and strain. With the proposed configuration, resolutions of +/- 2.8 degreesC/rootHz and +/- 13.9 muepsilon/rootHz are obtained for temperature and strain measurements, respectively.
2004
Autores
Rego, G; Marques, PVS; Salgado, HM; Santos, JL;
Publicação
SECOND EUROPEAN WORKSHOP ON OPTICAL FIBRE SENSORS: PROCEEDINGS
Abstract
The radiation emitted by an optical fiber during heating due to an electric arc discharge was detected using a Cronin spectrometer. The fitting of the emission spectrum to the blackbody radiation, allowed the estimation of the temperature range attained by the fiber.
2003
Autores
Romero, R; Frazao, O; Floreani, F; Zhang, L; Marques, PVS; Salgado, HM;
Publicação
HIGH-SPEED NETWORKS AND MULTIMEDIA COMMUNICATIONS, PROCEEDINGS
Abstract
Two different architectures of multiplexers/demultiplexers based on 4 x 1 and 1 x 4 configurations are discussed. These architectures are implemented using apodized fibre Bragg gratings as optical filters and optical circulators. The spectral characteristics of the devices for channel separations of 100 GHz and 50 GHz are analysed and their performance is evaluated. Optical switch and cross-connect configurations are also demonstrated.
2003
Autores
Melo, M; Frazao, O; Romero, R; Andre, PS; Marques, PVS; Salgado, HM; Santos, JL;
Publicação
PROCEEDINGS OF THE INTERNATIONAL 2003 SBMO/IEEE MTT-S INTERNATIONAL MICROWAVE AND OPTOELECTRONICS CONFERENCE - IMOC 2003, VOLS I AND II
Abstract
In this paper we present and evaluate the spectral response of uniform gratings written in different tapered core sections of single mode fibre. This combination of uniform gratings and tapers leads to three, types of Chirped Fibre Bragg Gratings with different reflection spectra and different mechanical properties. These devices are characterized in function of the applied strain, showing interesting chirp tunability.
2004
Autores
Romero, R; Frazao, O; Floreani, F; Zhang, L; Marques, PVS; Salgado, HM;
Publicação
Proceedings of the IASTED International Conference Communication Systems and Networks
Abstract
A multiplexer/demultiplexer for 100 GHz channel spacing based on chirped fibre Bragg gratings with different bandwidths and optical circulators is presented. The spectral characteristics, specifications and operation of these passive devices are described, showing its potential use in DWDM applications.
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