Real-time distributed fiber microphone based on phase-OTDR

The use of an optical fiber as a real-time distributed microphone is demonstrated employing a phase-OTDR with direct detection. The method comprises a sample-and-hold circuit capable of both tuning the receiver to an arbitrary section of the fiber considered of interest and to recover in real-time the detected acoustic wave. The system allows listening to the sound of a sinusoidal disturbance with variable frequency, music and human voice with similar to 60 cm of spatial resolution through a 300 m long optical fiber24262959729602CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQnão temThe authors would like to thank the Conselho Nacional de Pesquisa (CNPq - Brazil) funding agency, the Centro de Pesquisa Sueco-Brasileiro (CISB), the Linnaeus Center in Advanced Optics and Photonics (ADOPT), the Swedish Research Council VR and the European ITN FINESSE – GA 722509