Photon-counting Brillouin optical time-domain reflectometry based on up-conversion detector and fiber Fabry-Perot scanning interferometer

TL;DR

This paper introduces a photon-counting BOTDR system utilizing an up-conversion detector and fiber Fabry-Perot interferometer, enabling high-resolution, simplified, and efficient Brillouin spectrum measurement along optical fibers.

Contribution

It presents a novel photon-counting BOTDR setup with enhanced spectral resolution and simplified data processing compared to conventional coherent detection methods.

Findings

Successful measurement of Brillouin spectra along 10 km fiber

Simultaneous analysis of power, spectral width, and frequency center

Effective temperature and stain sensing demonstrated

Abstract

A direct-detection Brillouin optical time-domain reflectometry (BOTDR) is proposed and demonstrated by using an up-conversion single-photon detector and a fiber Fabry-Perot scanning interferometer (FFP-SI). Taking advantage of high signal-to-noise ratio of the detector and high spectrum resolution of the FFP-SI, the Brillouin spectrum along a polarization maintaining fiber (PMF) is recorded on a multiscaler with a small data size directly. In contrast with conventional BOTDR adopting coherent detection, photon-counting BOTDR is simpler in structure and easier in data processing. In the demonstration experiment, characteristic parameters of the Brillouin spectrum including its power, spectral width and frequency center are analyzed simultaneously along a 10 km PMF at different temperature and stain conditions.