Simultaneous independent temperature and strain measurement using in-fibre Bragg grating sensors

A new technique for the simultaneous, independent measurement of temperature and strain using in-fibre Bragg grating sensors is proposed and demonstrated. Two Bragg gratings with closely spaced centre wavelengths are written either side of a splice between two fibres of different diameter. The gratings show similar temperature sensitivities but different strain responses to an applied stress. Maximum errors of /spl plusmn/17 /spl mu//spl epsiv/ and /spl plusmn/1/spl deg/ are reported over 2500 /spl mu//spl epsiv/ and 120/spl deg/C measurement ranges.