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Koichi Yamakawa - One of the best experts on this subject based on the ideXlab platform.

Miguel Gonzalez-herraez - One of the best experts on this subject based on the ideXlab platform.

  • Laser Phase-Noise Cancellation in Chirped-Pulse Distributed Acoustic Sensors
    Journal of Lightwave Technology, 2018
    Co-Authors: María R. Fernández-ruiz, Juan Pastor-graells, Hugo F. Martins, Sonia Martín-lópez, Antonia García Ruiz, Miguel Gonzalez-herraez
    Abstract:

    Distributed acoustic sensors based on Chirped-Pulse phase sensitive-optical time-domain reflectometry (Chirped-Pulse ΦOTDR) have proven capable of performing fully distributed, single shot measurements of true strain or temperature perturbations, with no need for frequency scanning or phase detection methods. The corresponding refractive index variations in the fiber are revealed in the Chirped-Pulse ΦOTDR trace through a local temporal shift, which is evaluated using trace-to-trace correlations. The accuracy in the detection of this perturbation depends upon the correlation noise and the coherence of the laser source. In this paper, we theoretically and experimentally analyze the impact of the laser phase noise in Chirped-Pulse ΦOTDR. In particular, it is shown that the noise in the readings of strain/temperature variations scales directly with the frequency noise power spectral density of the laser. To validate the developed model, an experimental study has been performed using three lasers with different static linewidths (5 MHz, 50 kHz, and 25 kHz), i.e., with different phase noise. Besides, we present a simple technique to mitigate the effect of the laser phase noise in Chirped-Pulse ΦOTDR measurements. The proposed procedure enables to detect perturbations with high signal-to-noise ratio even when using relatively broad linewidth (i.e., comparatively high phase noise) lasers. Up to 17 dB increase in signal-to-noise ratio has been experimentally achieved by applying the proposed noise cancellation technique.

  • Laser Phase-noise Cancellation in Chirped-Pulse Distributed Acoustic Sensors
    Journal of Lightwave Technology, 2017
    Co-Authors: María R. Fernández-ruiz, Juan Pastor-graells, Hugo F. Martins, Sonia Martín-lópez, Antonia García Ruiz, Miguel Gonzalez-herraez
    Abstract:

    IEEE Distributed acoustic sensors (DAS) based on Chirped-Pulse phase sensitive-optical time-domain reflectometry (Chirped-Pulse < formula > < tex > $\Phi$ < /tex > < /formula > OTDR) have proven capable of performing fully distributed, single shot measurements of true strain or temperature perturbations, with no need for frequency scanning or phase detection methods. The corresponding refractive index variations in the fiber are revealed in the Chirped-Pulse < formula > < tex > $\Phi$ < /tex > < /formula > OTDR trace through a local temporal shift, which is evaluated using trace-to-trace correlations. The accuracy in the detection of this perturbation depends upon the correlation noise and the coherence of the laser source. In this work, we theoretically and experimentally analyze the impact of the laser phase noise in Chirped-Pulse < formula > < tex > $\Phi$ < /tex > < /formula > OTDR. In particular, it is shown that the noise in the readings of strain/temperature variations scale directly with the frequency noise power spectral density of the laser. To validate the developed model, an experimental study has been performed using three lasers with different static linewidths (5 MHz, 50 kHz and 25 kHz), i.e., with different phase noise. Besides, we present a simple technique to mitigate the effect of the laser phase noise in Chirped-Pulse < formula > < tex > $\Phi$ < /tex > < /formula > OTDR measurements. The proposed procedure enables to detect perturbations with high signal-to-noise ratio even when using relatively broad linewidth (i.e. comparatively high phase noise) lasers. Up to 17 dB increase in SNR has been experimentally achieved by applying the proposed noise cancellation technique.

  • Chirped-Pulse Phase-Sensitive Optical Time-Domain Reflectometry
    2016 Asia Communications and Photonics Conference (ACP), 2016
    Co-Authors: Miguel Gonzalez-herraez, Juan Pastor-graells, María R. Fernández-ruiz, Hugo F. Martins, Antonia García Ruiz, Pedro Corredera, Sonia Martín-lópez
    Abstract:

    We review our recent work on Chirped-Pulse phase-sensitive optical time-domain reflectometry along optical fibers and its application in the measurement of true nanostrain variations in the kHz frequency range over lengths up to 20 km.

Masayuki Fujita - One of the best experts on this subject based on the ideXlab platform.

Yutaka Akahane - One of the best experts on this subject based on the ideXlab platform.

Gerard Mourou - One of the best experts on this subject based on the ideXlab platform.