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Low‐frequency detection of acoustic signals using fiber as an ultrasonic guide with a distant in‐fiber Bragg grating
Author(s) -
Leal Wescley A.,
Carneiro Mateus B. R.,
Freitas Taiane A. M. G.,
Marcondes Cláudia B.,
Ribeiro Ricardo M.
Publication year - 2018
Publication title -
microwave and optical technology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.304
H-Index - 76
eISSN - 1098-2760
pISSN - 0895-2477
DOI - 10.1002/mop.31061
Subject(s) - fiber bragg grating , materials science , demodulation , optics , ultrasonic sensor , detector , bandwidth (computing) , phosfos , acoustics , optical fiber , optoelectronics , fiber optic sensor , plastic optical fiber , telecommunications , physics , computer science , channel (broadcasting)
This article shows the development of a photonic detector of low‐frequency ultrasonic signals. These signals latter reach a sensitive single‐mode optical fiber as an acoustic guide conveying the signals (around 43 kHz) over 70 cm to a distant and protected in‐fiber Bragg grating. The grating reflects a spectrum centered around 1550 and 2.6 nm bandwidth and is interrogated by a tunable laser in their linear and most sensitive region. As a result, real‐time passive demodulation of communication or monitoring of ultrasonic signals propagating through solid materials is possible. The detector may also be applied to other physical media. In this study, a new passive technique to thermally desensitize the fiber‐Bragg gratings (FBG) is also proposed, though the proposed technique is not experimentally tested.