Abstract
Recently, we have proposed a Brillouin optical correlation-domain reflectometry (BOCDR) to measure the distribution of strain along an optical fiber from a single end of the fiber, and obtained 13-mm spatial resolution and 50-Hz sampling rate. These resolution, which is directly related to the signal-to-noise (SN) ratio, and sampling rate were limited by the use of an electrical spectrum analyzer (ESA). In this paper, we examine the possibilities of improvements of the SN ratio and the sampling rate as well as a cost reduction with a new BOCDR system based on optical heterodyne detection that uses a single-sideband modulator and fast Fourier transform and contains no ESA. In the experiment, the SN ratio was not as good as that of the conventional BOCDR, but the sampling rate was enhanced to 400 Hz. In addition, noise inherent to this scheme was observed and discussed.
