We have demonstrated an ultralong (up to 85 km in length) all-fibre Raman temperature sensor which utilises SMF-28 standard single-mode telecom fibre and a 1.63-mm probe signal source. The probe signal from the laser diode is amplified by a Raman fibre amplifier. The temperature along a 85-km-long fibre line has been measured with an accuracy of 8 °C and spatial resolution of 800 m or better.
- Distributed temperature sensor
- Fibre-optic link.
- Raman scattering
- fibre-optic link
- distributed temperature sensor