Listar Dpto. Ingeniería Eléctrica y Electrónica - Ingeniaritza Elektriko eta Elektronikoa Saila por tema "Fiber optics sensors"
Mostrando ítems 1-20 de 20
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46-km-long Raman amplified hybrid double-bus network with point and distributed Brillouin sensors
We experimentally demonstrate a 46-km hybrid network that combine point and distributed Brillouin sensors. The proposed sensor network multiplexes low-cost intensity point sensors based on fiber-optic tapers, which are ... -
BOTDA measurements tolerant to non-local effects by using a phase-modulated probe wave and RF demodulation
We demonstrate a Brillouin optical time domain analysis sensor based on a phase modulated probe wave and RF demodulation that provides measurements tolerant to frequency dependent variations of the pump pulse power induced ... -
Brillouin optical time-domain analysis sensor assisted by Brillouin distributed amplification of pump pulses
We demonstrate the extension of the measurement range of Brillouin optical time-domain analysis (BOTDA) sensors using a distributed Brillouin amplifier (DBA). The technique is based on injecting a DBA pump wave in the ... -
Brillouin optical time-domain analysis sensor with pump pulse amplification
We demonstrate a simple technique to provide conventional Brillouin optical time-domain analysis sensors with mitigation for pump pulse attenuation. The technique is based on operating the sensor in loss configuration so ... -
Detrimental effects in Brillouin distributed sensors caused by EDFA transient
We investigate the deleterious effect and the error in Brillouin optical time-domain analyzers induced by the combination of a low extinction ratio pulse generation with the transient behavior of erbium-doped fiber amplifiers. -
Dynamic BOTDA measurements based on Brillouin phase-shift and RF demodulation
We demonstrate a novel dynamic BOTDA sensor based, for the first time to our knowledge, on the use of the Brillouin phase shift in addition to the conventional Brillouin gain. This provides the advantage of measurements ... -
Egituren egoeraren monitorizaziorako zuntz optikoan oinarritutako sentsore sinplifikatua
Brillouin hedatuko denbora eremu optikoaren analisian (BOTDA) oinarritutako sentsoreak, estruktura handien (100 km luzerako estrukturak) deformazioa eta tenperatura neurtzeko gaitasuna dute. Lan honetan, BOTDA konfigurazio ... -
Fringe generation with non-uniformly coated long-period fiber gratings
In this work, the spectral characteristics of non-uniform symmetrically ring shaped coatings deposited on long-period fiber gratings (LPFGs) have been theoretically and experimentally investigated. To optimize the ... -
Humidity sensor based on Bragg gratings developed on the end facet of an optical fiber by sputtering of one single material
The refractive index of sputtered indium oxide nanocoatings has been altered just by changing the sputtering parameters, such as pressure. These induced changes have been exploited for the generation of a grating on the ... -
Mode transition in complex refractive index coated single-mode–multimode–single-mode structure
By coating a single-mode–multimode–single-mode (SMS) structure with a high refractive index thin-film it is possible to obtain a transition of modes for specific combinations of thin-film thickness, thinfilm refractive ... -
Optimization in nanocoated D-shaped optical fiber sensors
Nanocoated D-shaped optical fibers have been proven as effective sensors. Here, we show that the full width at half minimum (FWHM) of lossy mode resonance can be reduced by optimizing the nanocoating width, thickness and ... -
Phasorial differential pulse-width pair technique for long-range Brillouin optical time-domain analysis sensors
We introduce a novel phasorial differential pulse width pair (PDPP) method for Brillouin optical time domain analysis (BOTDA) sensors that combines spatial resolution enhancement with increased tolerance to non local ... -
Refractometric sensors based on multimode interference in a thin-film coated singlemode– multimode–single-mode structure with reflection configuration
Thin-film coated single-mode–multimode–single-mode (SMS) structures have been analyzed both theoretically and experimentally with the aim of detecting different refractive indices. By adequate selection of the thickness ... -
Second-order non-local effects mitigation in BOTDA sensors by tracking the BFS profile
We demonstrate a technique to mitigate the residual second-order non-local effects in Brillouin optical time-domain analysis (BOTDA) sensors in which the Brillouin frequency shift (BFS) profile is not uniform along the ... -
Second-order nonlocal effects mitigation in Brillouin optical time-domain analysis sensors by tracking the Brillouin frequency shift profile of the fiber
We report on an additional limitation that has been found in Brillouin optical time-domain analysis (BOTDA) sensors due to the so-called second-order nonlocal effects (NLE). Second-order NLE appear in BOTDA setups that ... -
Sensitivity enhancement in low cutoff wavelength long-period fiber gratings by cladding diameter reduction
The diameter of long-period fiber gratings (LPFGs) fabricated in optical fibers with a low cutoff wavelength was be reduced by hydrofluoric acid etching, enhancing the sensitivity to refractive index by more than a factor ... -
Sensitivity optimization with cladding-etched long period fiber gratings at the dispersion turning point
This work presents a refractive index sensor based on a long period fiber grating (LPFG) made in a reduced cladding fiber whose low order cladding modes have the turning point at large wavelengths. The combination of ... -
Spectral evolution with incremental nanocoating of long period fiber gratings
The incremental deposition of a thin overlay on the cladding of a long-period fiber grating (LPFG) induces important resonance wavelength shifts in the transmission spectrum. The phenomenon is proved theoretically with ... -
Synthesis of Brillouin frequency shift profiles to compensate non-local effects and Brillouin induced noise in BOTDA sensors
We present a novel technique for Brillouin optical time domain analysis (BOTDA) sensors that simultaneously compensates non local effects and reduces Brillouin noise. The technique relies on the wavelength modulation of ... -
Ultrahigh-sensitivity sensors based on thin-film coated long period gratings with reduced diameter, in transition mode and near the dispersion turning point
The mode transition and the dispersion turning point have been explored for optimization of thin-film coated long period fiber gratings during the last years. In this work and additional parameter, the cladding diameter, ...