Simultaneous Measurement of Strain and Curvature with a Fiber Optic Singlemode-Multimode-Singlemode Structure

Abstract

Current paper reports a novel approach for simultaneous measurement of strain and curvature by a single mode-multimode-single mode (SMS) sensor based on different dependencies of mode propagation constants on the perturbations. For that, optical transmission spectra of SMS sensor are to be measured and processed with a fast Fourier transform (FFT). FFT analysis allows to decompose the complex interference signal onto components corresponding to individual mode groups. This, in turn, allowed us to carry out simultaneous measurement of strain and curvature, which, to the best of our knowledge, was done for the first time with a SMS sensor.