Distributed fiber sensing technology: Currents and challenge

Abstract

In this paper, distributed fiber sensing technologies are explained, showing principles and applications. Time domain technologies have been developed, at first, as ways to analyze the distributed information along the fiber. For example, in distributed strain measurement through the nature of scattering, basic systems showed limitation in spatial resolution of about 1m. However, novel phenomena and new systems have recently been proposed, and the resolution has been much improved. Optical correlation domain techniques, in which interference of continuous lightwaves is manipulated to obtain the distributed information, have already realized superior performances, such as 1.6 mm spatial resolution and 1 kHz sampling rate, in the fiber Brillouin distributed strain sensing. Applications, such as aircraft health monitoring, have also been demonstrated. Recently, Brillouin dynamic grating in a polarization maintaining fiber has been studied, and created various novel applications, including simultaneous distributed measurement of strain and temperature. With the correlation domain technique, other schemes, such as multiplexing systems for long-length FBG distributed sensors, have also been developed.