Brillouin optical correlation domain analysis with 2 MHz sampling rate capable of monitoring the strain wave propagation along an optical fiber

Abstract

High-speed Brillouin optical correlation domain analysis is demonstrated using lock-in-free balanced detection of orthogonally-polarized probe sidebands. The proposed system enables polarization-independent measurement on local Brillouin gain spectra at a sampling rate of 2 mega samples per second (2 MSa/s) with a spatial resolution of 5 cm. The full distribution map of Brillouin frequency along a 5.2 m standard single-mode fiber is acquired with a 10 kHz repetition rate and 144 sampling points. This high-performance system allows for the analysis of axial strain wave occurrence and propagation along a stretched optical fiber, induced by the popping noise of a powered speaker. © Optica Publishing Group 2023, © 2023 The Author(s)