Distributed sensors based on phase-optical time-domain reflectometry (phase-OTDR) are suitable for aircraft health monitoring due to electromagnetic interference immunity, small dimensions, low weight and flexibility. These features allow the fiber embedment into aircraft structures in a nearly non-intrusive way to measure vibrations along its length. The capability of measuring vibrations on avionics structures is of interest for what concerns the study of material fatigue or the occurrence of undesirable phenomena like flutter. In this work, we employed the phase-OTDR technique to measure vibrations ranging from some dozens of Hz to kHz in two layers of composite material board with embedded polyimide coating 0.24 numerical aperture single-mode optical fiber.
KEYWORDS: Optical amplifiers, Raman spectroscopy, Backscatter, Sensing systems, Temperature metrology, Signal attenuation, Data modeling, Single mode fibers, Calibration, Standards development
The distributed temperature sensor system based in the spontaneous Raman backscattering is demonstrated for the first time to our knowledge, using a commercial OTDR (Optical Time Domain Reflectometer) and a standard erbium doped fiber amplifier (EDFA) with controlled gain. We evaluated this approach in a 30 km of single mode fiber using an OTDR pulse width of 100 ns and an EDFA with 17 dBm of output power.
Joao Rosolem, Claudio Hortencio, Claudio Floridia, Danilo Dini, Rivael Penze, Bruno Aires, Fabio Bassan, Rodrigo Morbach, Eduardo da Costa, Felipe Salgado, Rodrigo Peres, João Paulo Fracarolli, Marcus Vinícius Santana, Augusto Cezar Gregatti, Guilherme Muniz, Gerson Amadeo, Gilson Carvalho, Fernando Pertile, Luis Fernando Melegari, Heloisa Herreros, Marcelo Kurokawa, Luis de Avila
This paper presents the results of a field test of a multi-parameters' monitoring network using FBGs adapted directly in the conventional instruments of two dams which are in full operational capability. We presented the details of the design and tests of the sensor’s network, such as, the sensors adaptation, the resolution comparison between the conventional instruments and the FBGs, the network topology, the spectral occupancy distribution considering the parameters optical bandwidth and also the temperature compensation for FBGs, the number of sensors by fiber and the performance of the FBGs sensors compared with the conventional instruments used in the Dams.
A silicon nitride directional coupler filled with toluene is proposed as temperature sensor. This liquid material has a high thermo-optic coefficient, which allows large variations on its refractive index in function of temperature variations. Simulations were performed to obtain the sensor's sensitivities, which measured on the output ports (P2, P3) of the structure are 0:11392= °C and 0:11499= °C, respectively.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.