OPTICAL SENSING DEVICE CONTAINING FIBER BRAGG GRATINGS

摘要

A new optical sensing device containing fiber Bragg gratings (26), a scanning bandpass filter (28), an interferometer (40) and multiple photodetectors (44, 46, 48) is disclosed. The present invention also describes a new system and method for fibre Bragg grating sensor interrogation and multiplexing. The new system combines a scanning Fabry-Perot bandpass filter used to wavelength-multiplex multiple gratings in a single fiber, and an unbalanced Mach-Zehnder fibre interferometer made with a 3x3 coupler to detect strain-induced wavelength shifts.