Open AccessCharacterization of stimulated Brillouin scattering in a circular-core two-mode fiber using optical time-domain analysis
Author(s) -
An Liu,
Qian Hu,
William Shieh
Publication year - 2013
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.21.031894
Subject(s) - brillouin scattering , optics , brillouin zone , optical fiber , core (optical fiber) , time domain , physics , scattering , materials science , computer science , computer vision
We show characterization of stimulated Brillouin scattering (SBS) in a circular-core two-mode fiber (c-TMF) using Brillouin optical time-domain analysis (BOTDA) with a pulsed pump and a counterpropagating continuous wave probe. By using two free-space mode combiners (FSMCs), we can launch any combination of spatial modes into both ends of the c-TMF. Combined with coherent detection, measurement of distributed Brillouin gain spectra (BGS) is achieved for all possible counter-propagating spatial mode pairs with high spectral resolution and stability. Both intra- and inter-modal SBS are investigated for the c-TMF. The inter-modal SBS between two degenerate LP11 modes (LP11a/LP11b) is demonstrated for the first time. From the Brillouin frequency shift (BFS) measured in each intra-modal SBS, the distributed modal birefringence between non-degenerate modes (LP01/LP11) and degenerate LP11 modes is obtained. The proposed setup can potentially be used as a c-TMF based distributed Brillouin sensor.