Research on the distributed measurement of temperature based on Brillouin scattering effect using a single-photon detector

Utilizing the single-photon detector, a direct-detection single-end Brillouin optical-fiber sensor is proposed and experimentally demonstrated for distributed temperature information measurement, which is an excellent candidate for the demodulation of frequency shift from Brillouin gain spectrum in conventional Brillouin schemes with coherent detection and frequency sweep. In our scheme, the ratio of the backscattered Rayleigh component and the Brillouin anti- Stokes signal is used to evaluate the ambient temperature along the fiber under test. Proof-of-concept experiments demonstrate 20dB dynamic range over 34km sensing fiber with a 0.96°C temperature error. In view of the good characteristics we achieved now, the photon-counting distributed Brillouin temperature sensor may be used in practical engineering fields such as smart grid.