Abstract
A multimode optical fiber supports excitation and propagation of a pure single optical mode, i.e., the field pattern that satisfies the boundary conditions and does not change along the fiber. When two counterpropagating pure optical modes are excited, they could interact through the stimulated Brillouin scattering (SBS) process. Here, we present a simple theoretical formalism describing SBS interaction between two individual optical modes selectively excited in an acoustically isotropic multimode optical fiber. Employing a weakly guiding step-index fiber approach, we have built an analytical expression for the spatial distribution of the sound field amplitude in the fiber core and explored the features of SBS gain spectra, describing the interaction between modes of different orders. In this way, we give a clear insight into the sound propagation effects accompanying SBS in multimode optical fibers, and demonstrate their specific contributions to the SBS gain spectrum.
Original language | English |
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Article number | 1715 |
Number of pages | 17 |
Journal | Sensors |
Volume | 23 |
Issue number | 3 |
DOIs | |
Publication status | Published - 3 Feb 2023 |
Bibliographical note
Copyright © 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).Funding Information:
A.F. is supported by the European Union’s Horizon 2020 research and innovation program (H2020-MSCA-IF-2020, #101028712). E.R. acknowledges the financial support from the Engineering and Physical Sciences Research Council (EPSRC, #EP/R024898/1). D.K. is grateful for the support from the Ministry of Science and Higher Education of the Russian Federation (project #075-15-2021-581) and the Russian Science Foundation (#22-72-10072).
Publisher Copyright:
© 2023 by the authors.
Keywords
- Brillouin imaging
- distributed Brillouin sensing
- mode-division multiplexing
- multimode optical fiber
- optical fiber amplifiers
- stimulated Brillouin scattering