(IEEE / OSA, 2009) Fernández Vallejo, Montserrat; Pérez Herrera, Rosa Ana; Elosúa Aguado, César; Díaz Lucas, Silvia; Urquhart, Paul; Bariáin Aisa, Cándido; López-Amo Sáinz, Manuel; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
We report the experimental demonstration of two configurations of an amplified optical fibre double ring network for the multiplexing of sensors. The networks are designed to be inherently resilient to fibre failures because they enable simultaneous interrogation of all the optical fibre sensors using both rings. The first design demonstrates the feasibility of the so called 'dedicated protection' and the second one 'shared
protection' for fibre optic intensity sensors. Raman amplification is used to overcome the losses of the couplers used in the rings, providing power transparency. The first network uses Raman amplification in both constituent rings but in the second one Raman pumping is activated only when a fibre failure occurs. We demonstrate how the topology allows the received powers from the sensors to be equalized.
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.
