Using the Phase Response of Fiber Bragg Gratings for Measurement Applications

Fiber Bragg gratings have been used in optical sensor systems for a long time. The conventional read-out is based on an amplitude evaluation, recent studies consider also the utilization of the group delay characteristic. This paper proposes a novel read-out approach that incorporates the direct evaluation of a fiber Bragg grating’s phase response. Experimental setups involving electronic vector network analyzers as well as just signal generators and analog-to-digital conversion are explained. The method has been evaluated with respect to real measurement tasks and shows promising results.