Singlemode-multimode-singlemode fiber structures (SMS) based on distinct sections of a pure silica multimode fiber (coreless-MMF) with diameters of 125 and 55 µm, were reported for the measurement of curvature and temperature. The sensing concept relies on the multimode interference that occurs in the coreless-MMF section and, in accordance with the length of the MMF section used, two fiber devices were developed: one based on a bandpass filter (self-image effect) and the other on a band-rejection filter. Maximum sensitivities of 64.7 nm·m and 13.08 pm/°C could be attained, for curvature and temperature, respectively, using the band-rejection filter with 55 µm-MMF diameter. A proof of concept was also explored for the simultaneous measurement of curvature and temperature by means of the matrix method.
© 2012 IEEE
Susana Silva, Edwin G. P. Pachon, Marcos A. R. Franco, Pedro Jorge, J. L. Santos, F. Xavier Malcata, Cristiano M. B. Cordeiro, and Orlando Frazão, "Curvature and Temperature Discrimination Using Multimode Interference Fiber Optic Structures—A Proof of Concept," J. Lightwave Technol. 30, 3569-3575 (2012)