Long-distance Φ-OTDR with a flexible frequency response based on time division multiplexing.
Opt Express
; 29(21): 32833-32841, 2021 Oct 11.
Article
em En
| MEDLINE
| ID: mdl-34809106
ABSTRACT
In this study, a long-distance phase-sensitive optical time domain reflectometry (Φ-OTDR) with a flexible frequency response based on time division multiplexing is proposed and experimentally demonstrated. Distributed flexible frequency vibration sensing over long distance can be realized by reconfiguring the system layout in a time-division-multiplexed manner by re-routing the Rayleigh backscattered signals for segmented processing with extra erbium-doped fiber amplifiers added only instead of any other complex signal amplification or pulse modulation mechanisms. Through time-division-multiplexed reconfiguration, the tradeoff between sensing distance and vibration frequency response in Φ-OTDR system is largely relieved. Compared with the traditional system layout, the proposed system allows a flexible frequency response in each sensing fiber segment without any crosstalk among them. In experiments, distributed vibration sensing with a frequency response up to 4.5 kHz is achieved over a sensing distance of 60km by the proposed system, which is not possible in a conventional Φ-OTDR system. Furthermore, the frequency response flexibility of the proposed system is further verified by successfully identifying a vibration event with a frequency of up to 20 kHz at the end of a 52-km-long fiber.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
Opt Express
Assunto da revista:
OFTALMOLOGIA
Ano de publicação:
2021
Tipo de documento:
Article