title: Distributed measurement of static strain in an optical fiber with multiple bragg gratings at nominally equal wavelengths.
abstract: The Fourier transform relationship between the reflected light froma Bragg grating and the complex spatial modulation of the Bragg grating is used to produce a distributed strain sensing system. A tunable external cavity diode laser along with a reference reflector in anoptical fiber are used to produce a measurement of the phase and amplitude of the reflected light from the modulated Bragg grating as a function of wavelength. The system is demonstrated with 22 Bragg gratings in a single fiber on a cantilever beam and compared with foil strain gauge readings.
authors.forename: M
authors.initials: M
authors.lastname: Froggatt
authors.forename: J
authors.initials: J
authors.lastname: Moore