Enhancement of multiplexing capability of low-coherence interferometric fiber sensor array by use of a loop topology

A novel technique for enhancing the multiplexing capability of low-coherence interferometric sensor array is proposed. The technique uses a fiber loop topology and allows for twice as many sensors as the conventional low-coherence reflectometry system to be multiplexed. Power budget and signal analyses for different sizes of sensor array are performed. A ten-sensor system was experimentally demonstrated and applied for quasi-distributed temperature measurement. An additional advantage of the technique is that it provides an extra degree of redundancy through the bidirectional interrogation of the sensor array and thus improves the system reliability.