A remote long-period grating sensor with electrical interrogation assisted by Raman amplification

Abstract

In this work, we present a method to predict the behaviour of a remote optical fiber sensor system based on a long period grating, Raman amplification and electrical interrogation were investigated. The interrogation unit is composed by two fiber Bragg gratings modulated by two piezoelectrics transductors. Optical fiber sensor systems are typically limited to operate at distances of only few kilometers due to the attenuation effects and noise that adversely affects the performance of the sensor interrogation process. We present experimental and simulation results obtained in the context of analysis of remote optical fiber sensors. The simulation models use numerical methods to compute the Raman interaction between the pumps and the sensor signals and allow speeding up the analyses regarding the setup to be experimentally implemented to measure environmental temperature. The results obtained show that under Raman amplification the power ratio between the two central wavelengths of the FBGs has a linear relation with the change of the LPG resonance induced by temperature variation.