2009
Authors
Aref, SH; Frazao, O; Caldas, P; Ferreira, LA; Araujo, FM; Santos, JL; Latifi, H; Ballato, J; Her, T; Farahi, F;
Publication
Proceedings of SPIE - The International Society for Optical Engineering
Abstract
In this work, interferometric sensors based on antiresonance reflecting waveguide (ARROW) fibers were developed and their performances were characterized for measurement of physical parameters, particularly strain and temperature. Two types of ARROW fibers were considered and signal demodulation was achieved using the white light interferometric technique. Application issues of sensing heads based on these fibers are also addressed. © 2009 SPIE.
2009
Authors
Viegas, D; Abad, S; Santos, JL; Ferreira, LA; Araujo, FM;
Publication
Proceedings of SPIE - The International Society for Optical Engineering
Abstract
A novel miniature fiber Bragg grating (FBG) based temperature probe is presented. The sensor design integrates a ushape lossless taper thus offering the advantages of a terminal temperature probe while enabling effective serial multiplexing. We report on the experimental validation of the temperature probe design demonstrating lossless operation and effective elimination of strain cross-sensitivity. © 2009 SPIE.
2009
Authors
Aref, SH; Amezcua Correa, R; Carvalho, JP; Frazao, O; Caldas, P; Santos, JL; Araujo, FM; Latifi, H; Farahi, F; Ferreira, LA; Knight, JC;
Publication
Proceedings of SPIE - The International Society for Optical Engineering
Abstract
In this work, sensitivity to strain, temperature and curvature of a sensor relying on modal interferometry in hollow-core photonic crystal fibre is studied. The sensing structure is simply a piece of hollow-core fibre connected in both ends to standard single mode fibre. An interference pattern that is associated to the interference of the light that propagates in the hollow core fundamental mode with light that propagates in other modes is observed. The phase of this interference pattern changes with the measurand interaction, which is the basis for considering this structure for sensing. The phase recovery is performed using a white light interferometric technique. © 2009 SPIE.
2009
Authors
Diaz Herrera, N; Viegas, D; Jorge, PAS; Navarrete, MC; Ferreira, LA; Araujo, FM; Santos, JL; Gonzalez Cano, A;
Publication
Proceedings of SPIE - The International Society for Optical Engineering
Abstract
A new interrogation method based on Fibre Bragg Gratings (FBG) for Surface Plamon Resonance (SPR) sensors in the region of refractive indices of aqueous solutions is described. Two FBGs are selected with their Bragg wavelengths at opposite sides of the plasmon resonance peak. The response of the system can be made independent of the fluctuations of the optical power source, and the linearity and the sensitivity of the sensor are improved. The use of the spectral selectivity of gratings for the interrogation of SPR sensors in different configurations is also promising in terms of multiplexing, temperature referencing or multiparameter detection. © 2009 SPIE.
2004
Authors
Luquin, E; Frazao, O; Ferreira, LA; Araujo, FM; Lopez Amo, M; Santos, JL;
Publication
Proceedings of SPIE - The International Society for Optical Engineering
Abstract
We present and demonstrate a high-resolution absolute-distance measurement system based on multiple-wavelength interferometry. The information on a cavity length is obtained by sampling a fringe of its spectral response at different wavelengths. This is achieved by simultaneously tuning multiple fiber Bragg gratings. For a two wavelength system, an unambiguous measurement range of 262 µm was obtained with a resolution of 14.3 nm.
2000
Authors
Jauregui, C; Araujo, FM; Ferreira, LA; Santos, JL; Lopez Higuera, JM;
Publication
Proceedings of SPIE - The International Society for Optical Engineering
Abstract
An all fiber interrogation technique for Bragg sensors is presented. It is based on generation of an electric carrier by modulating the coupling length of a wavelength division multiplexer. Results are given when both serrodyne and sinusoidal modulation formats are considered.
The access to the final selection minute is only available to applicants.
Please check the confirmation e-mail of your application to obtain the access code.