Simplified correlation-domain Brillouin sensor using plastic optical fiber

Abstract

To perform distributed strain and temperature measurement, we have recently developed simplified Brillouin optical correlation-domain reflectometry (S-BOCDR), in which the light Fresnel-reflected at the ends of the fiber under test (FUT) is used as a reference light. Here, we implement S-BOCDR using a plastic optical fiber (POF) as an FUT, which provides the following advantages over S-BOCDR using a standard silica single-mode fiber (SMF): (1) the beat signal of the Stokes light and the Fresnel-reflected light that is obtained at the interface between the POF and the SMF (the pigtail of an optical circulator) can be stabilized, and (2) the effect of the 0th correlation peak can be easily and effectively suppressed by exploiting a so-called Brillouin frequency shift-hopping phenomenon. We then experimentally demonstrate a distributed measurement and detect a 0.46-m-long heated POF section.