Intermodal fiber interferometer based on broadband light source and optical spectrum analyzer for external perturbations measurement

An intermodal fiber interferometer based on broadband light source and spectral signal processing is proposed and experimentally investigated. The influence of the parameters of the spectrum analyzer (scanning range and width of the instrumental spectral response function) on the output signal is demonstrated. It is shown that the method of correlation signal processing makes it possible to obtain linear and stable response to external fiber perturbations. The proposed interferometer scheme can be prospective for development of real-time sensors of physical quantities