Reduction of crosstalk in inline sensor arrays using inverse scattering

Abstract

Suppression of crosstalk in an FBG-based serially multiplexed interferometric sensor array is demonstrated by employing the layer peeling inverse scattering algorithm. A polarization resolved impulse response (array reflection Jones matrix versus time) is measured using dual pulse heterodyne interrogation with varying combinations of polarization states in the interrogating pulse pair, and used as input to the layer peeling algorithm. < -40 dB crosstalk is achieved with > 97% confidence in a sensor array with 5 % FBG reflectivity. This is a 15-20 dB improvement compared to interrogation without inverse scattering.