Multi-element Bragg-grating based fibre-laser strain sensor

Abstract

A fibre laser configuration is described which uses multiple fibre Bragg grating sensors as feedback elements. By tuning a wavelength selective filter located within the laser cavity over the gain bandwidth, the laser selectively lases at each of the Bragg wavelengths of the sensors, thus allowing strain induced shifts in the Bragg wavelengths to be monitored. A four sensor system is reported.