@ARTICLE {31638,
author={L. M. Sousa and J.  Vieira and M. Facão and G. Fernandes and R.N.  Nogueira and Ana M. Rocha},
doi={10.1109/JLT.2021.3094298},
journal={Journal of Lightwave Technology},
title={Long-period grating based coupler for multi-core fiber systems},
year={2021},
month={September},
volume={39},
number={18},
pages={5947-5953},
ISSN={0733-8724}
}