Link optimized few-mode fiber Raman distributed temperature sensors

A link optimized few-mode fiber-based Raman distributed temperature sensor is proposed to enhance the temperature resolution of the long-distance sensing system. Comprehensive theoretical analysis and experimental validation in contrast with the traditional single-mode fiber-based sensing link have been conducted to reveal the benefits provided by the optimization scheme. The temperature resolutions are about 3.8°C for the proposed fiber link at 20 km distance, leading to about 6.2°C improvement compared with the single-mode fiber (SMF) link. The total measurement is completed within 80 s over 20 km with a spatial resolution of 3 m.