High performance Brillouin distributed fibre sensor

We propose a novel configuration for a Brillouin distributed sensor based on Brillouin optical time domain analysis. This new configuration eliminates many intensity noise issues found in previous schemes. Resolution of 3.5 m all over a 47km single-mode fibre was achieved and resolution down to 30 cm in a few kilometre fibre. Noise reduction makes possible measurements with a 16 times averaging

Study of a progressive failure in soil using BEDS

In Geotechnical Engineering, progressive failure in soil-structure interaction is one of the least understood problems. It is difficult to study this phenomenon at laboratory scale, because of the large amount of strain gages required per unit length/area of the structure, which would interfere with the mechanical properties of both the structure and the soil. The recently developed Brillouin Echo Distributed Sensor (BEDS) technology overcomes this dilemma by distributed readings and 5cm spatial resolution. A laboratory pullout testing program has been carried out to verify applicability of BEDS for the study of progressive failure in the soil-structure interaction

Advanced Brillouin-based distributed optical fibre sensors with sub-meter scale spatial resolution

Classical configurations of Brillouin distributed optical fibre sensors show a spatial resolution limited by the phonon lifetime to 1 meter. Novel approaches can substantially overcome this limit through the prior activation of the acoustic wave

Distributed fiber sensing using Brillouin echoes

A simple physical description of the nonlinear optical interaction based on Brillouin echoes is presented. This technique makes potentially possible distributed Brillouin sensing down to centimeter spatial resolution while preserving the narrowband feature of the natural Brillouin gain spectrum. Experimental conditions for the generation of Brillouin echoes are described and demonstrations of distributed measurements using a 1 ns (10 cm) pulse are presented