Brillouin-based Fiber-optic Sensors Research Articles

Stationary Wavelet Transform Method for Distributed Detection of Damage by Fiber-Optic Sensors

AbstractBrillouin scattering–based fiber-optic sensors have been used in a number of applications, including monitoring of pipelines and well-casing damage in the oil and gas industry. The major attribute of these sensors is their capability for distributed sensing of strains along large sections of structures. For these reasons, Brillouin-based fiber-optic sensors have great potential for civil structural applications, such as in bridges. This study reports the investigation of the Brillouin optical time-domain reflectometer for assessing damage in structural members. The primary advantage in using the Brillouin optical time-domain reflectometer is the single-fiber installation and multidamage-detection capability for the entire structure. The challenge in using a Brillouin optical time-domain reflectometer for detection of localized damage is to overcome the effects of system noise and Brillouin frequency-peak shift distortions. The compound effects of noise and frequency-peak distortions result in disp...

Submillimeter crack detection with brillouin-based fiber-optic sensors

Submillimeter crack is detected with a dedicated fiber-optic strain cable, a 1-m-spatial-resolution ( <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">w</i> ) distributed Brillouin sensor and an advanced signal processing technique. The signal processing approach consists in spectrum shape analysis and multiple peaks detection.

Fiber-Optic Distributed Sensor Based on Hybrid Raman and Brillouin Scattering Employing Multiwavelength Fabry–PÉrot Lasers

We propose the use of standard multiwavelength Fabry–PErot (FP) lasers for distributed strain and temperature measurement in hybrid Raman- and Brillouin-based fiber-optic sensors. The multiple longitudinal modes of FP lasers allow for accurate spontaneous Raman scattering measurement and for simultaneous high-sensitivity coherent detection of the Brillouin frequency shift parameter for all longitudinal modes. Experimental results confirm great performance improvement in simultaneous strain and temperature measurement using a single optical fiber.