2006
Autores
Rego, GM; Marques, PVS; Santos, JL; Salgado, HM;
Publicação
OPTICS COMMUNICATIONS
Abstract
The underlying formation mechanisms and the properties of long-period gratings produced through arc discharges are intrinsically related to the temperature reached by the fibre during arc exposure. In this work, the determination of the fibre temperature was based on Plank's blackbody radiation law. The radiation emitted by the optical fibre during heating due to an electric arc discharge, detected using a Cronin spectrometer, was fitted to the emission spectrum of the blackbody radiation, allowing the estimation of the temperature range attained by the fibre. A peak temperature of 1400 +/- 50 degrees C was obtained.
2004
Autores
Romero, R; Frazao, O; Marques, PVS; Salgado, HM;
Publicação
OPTICS COMMUNICATIONS
Abstract
A dynamic dispersion compensation device using a chirped fibre Bragg grating with a ring geometry embedded in a composite laminated is proposed. A numerical model is presented and compared with the experimental setup. It is shown that the theoretical and experimental results are in good agreement. The tunability of the device is obtained by applying different radius of curvature to the ring structure, and thus producing non-linear variations in the spatial period of the chirped fibre Bragg grating, without changing the usable bandwidth.
2005
Autores
Rego, G; Falate, R; Kalinowski, HJ; Fabris, JL; Marques, PVS; Salgado, HM; Santos, JL;
Publicação
17th International Conference on Optical Fibre Sensors, Pts 1 and 2
Abstract
A compact sensor able to discriminate between temperature and strain related effects was implemented. The proposed sensing head comprises a single long-period grating with two sections written consecutively in the SMF-28 fiber, by the electric arc discharge technique, using different fabrication parameters. The sensor performance is based on the distinct temperature and strain sensitivity values presented by two neighbor resonances belonging to each grating section. The temperature and strain resolutions are +/- 0.1 degrees C and +/- 40 mu epsilon, 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.
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