Long-distance fiber Bragg grating sensor system based on hybrid Raman/erbium-doped fiber amplification

Abstract

ABSTRACT In this paper, a hybrid Raman and Erbium-doped fiber amplifier (Raman/EDFA) is first proposed for enhancementof the performance of long-distance fiber Bragg grating (FBG) sensor systems. The Raman fiber amplifier is used for achieving low-noise amplification of FBG signals while the EDFA arranged remotely is used for both the compensation of the fiber loss due to long-distance transmission and the illumination of remotely-located FBGsensors as a broadband source by using the residual Raman pump power to generate ASE light and by amplifyingthe transmission light of the FBGs located before the EDFA. Such a sensor system adopts the advantages of thelow noise feature ofthe distributed Raman amplifier and the high small-signal gain ofthe EDFA. Experimentalresults show that the performance of the sensor system has been improved significantly. A signal-to-noise ratio (SNR) of l3dB has been achieved for a 50km transmission distance, which is l0dB higher than that without amplification.