Fiber Bragg Grating Pair Interferometer Sensor with Enhanced Multiplexing Capacity

摘要

A new technique monitoring and multiplexing FBG pair interferometer sensors with linear chirped fiber laser is investigated. It demonstrates the enhanced multiplexing capacity over a conventional WDM FBG sensor system by allowing multiple sensors to share the same optical bandwidth. Fiber Bragg Grating (FBG) sensors have been widely used in temperature, strain and pressure measurements because they have very low excess optical loss, exhibit high sensitivity, can be monitored in a straightforward manner. Moreover, wavelength division multiplexing (W DM) allows a system to monitor multiple FBG sensors conneted along a single fiber. However, the multiplexing capacity of a conventioal WDM sensor system is limited, because FBGs have to be kept in different wavelength channels and crosstalk between neiborghing sensors generally should be avoided. In this report, a new FBG sensing scheme is introduced to provide improved measurement sensitivity for individual sensing elements and enhanced multiplexing capacity by allowing multiple sensors to share the same regime of the optical spectrum.