Novel interrogating system for fibre Bragg grating sensors using an acousto-optic tunable filter

Abstract

A new technique for the interrogation of in-fibre Bragg grating sensors using an acousto-optic tunable filter (AOTF) is demonstrated. The scheme involves frequency shift keying (FSK) of the RF drive to the AOTF to track the wavelength shifts of a Bragg grating. Experimental results are presented for temperature measurement. This technique provides a frequency-agile system, capable of rapid, random access and very wide tuning range.