46-km-long Raman amplified hybrid double-bus network with point and distributed Brillouin sensors

We experimentally demonstrate a 46-km hybrid network that combine point and distributed Brillouin sensors. The proposed sensor network multiplexes low-cost intensity point sensors based on fiber-optic tapers, which are able to measure vibrations in the 0.01 to 50 Hz frequency range. The sensor network with a double-bus is a low noise configuration, which offers a higher optical signal to noise ratio and dynamic range than a single-bus. Thus, the number of sensors to be multiplexed could increase or we could reach further distances. The system also deploys remote distributed Raman amplification to extend the sensing range.This work was supported in part by the Spanish Ministerio de Educación y Ciencia under Projects TEC2007-67987-C02-02 and TEC2010-20224-C02-01