Abstract

High sensing resolution in long-distance distributed fiber optic sensors, such as Brillouin Optical Time Domain Analysis (BOTDA), cannot be trivially achieved due to several issues including self-phase modulation, resolution-uncertainty trade-offs and fiber attenuation. These problems could be fixed by the use of differential pulse-pair techniques in combination with Raman amplification. In this work we present a Differential Pulse-width Pair (DPP) Raman-assisted BOTDA sensor, that can achieve 1 meter resolution in a 100 km range.