Multi-parameter fiber optic sensing setup based on spectral-overlap using Fabry-Perot interferometers

In this work, multi-parameter fiber optic sensing setup is demonstrated by the simultaneous analyses of curvature and transversal load. The experimental arrangement operates by using two compact all fiber Fabry-Perot interferometers. Using a 2x1 optical fiber coupler the reflected interference patterns provided by each interferometer are combined, consequently new interference spectrum is obtained. Overlapping interference spectra is generated, and when curvature and load are simultaneously applied, intensity and phase variations are independently observed. The load information is obtained through a wavelength shifting generated by one interferometer, meanwhile the curvature data were analyzed using the intensity modulation provided by the other interferometer. The load analysis presents sensitivity around 0.1nm/N and moreover the experimented curvature shows a resolution of 0.4*10 -3 cm -1 .