250 km ultra long remote sensor system based on a fiber loop mirror interrogated by an OTDR

Abstract

A 253 km ultra long remote displacement sensor system based on a fiber loop mirror interrogated by a commercial OTDR is proposed and experimentally demonstrated. The use of a fiber loop mirror increases the signal to noise ratio allowing the system to interrogate sensors placed 253 km away from the monitoring system without using any optical amplification. The displacement sensor was based on a long period grating spliced inside of the loop mirror, which modifies the mirror reflectivity accordingly to the applied displacement. ; This work was supported by the European Cooperation in Science and Technology (COST) Action TD1001: Novel and Reliable Optical Fibre Sensor Systems for Future Security and Safety Applications (OFSeSa) and by the Spanish Government through project TEC2010-20224-C02-01.