Abstract
In this paper, we propose a synthetic approach to improve the spatial resolution of Brillouin optical time-domain reflectometry (BOTDR). Due to the uncertainty relation between position and frequency, the spatial resolution of a conventional BOTDR system has been limited to about one meter. It is shown that this limit could be overcome by the synthetic approach. In the synthetic approach, a Brillouin spectrum is constructed by combining several spectrums obtained by BOTDR measurements with different pump lights and low-pass filters. The pump lights and low-pass filters are composed of short and long elements with phase differences. By using the synthetic Brillouin spectrum, it is possible to estimate the Brillouin frequency shift with an arbitrary spatial resolution. This property is verified by a numerical simulation.
