A hybrid star-ring architecture for fiber Bragg grating sensor system

In this letter, we present a hybrid star-ring architecture for a highly reliable fiber Bragg grating (FBG) sensor system and demonstrate its effectiveness. The main trunk of the proposed sensor network is star topology and the sensing branches comprise a series of concatenated ring subnets. The weakness in reliability of the star network is overcome by the ring subnets with a self-healing function based on the reconfigurable optical switches between each subnet. To enhance the signal-to-noise ratio (SNR) of the sensor system, we adopt a linear-cavity FBG laser scheme to construct our proposed hybrid star-ring architecture. Such a fiber-laser scheme results in the SNR over 48 dB for the sensor network. The network survivability of a ten-point FBG sensor is experimentally examined. It is shown that the proposed FBG sensor system can increase the reliability of a sensing network.