2022 Volume 19 Issue 18 Pages 20220379
Recently, a very interesting behavior of crosstalk (XT) between diagonal cores (diagonal XT) in a square-layout uncoupled four-core fiber (UC-4CF) that grows quadratically with fiber length has been reported. In this paper, the behavior of intercore XT in square-layout UC-4CFs is investigated on the basis of a coupled-power theory. To make it easy to understand the physical mechanism of intercore XT behavior, we derive an approximate solution of coupled-power equations. We show that there exists a range of fiber lengths within which the diagonal XT grows quadratically. Finally, we propose a heterogeneous square-layout UC-4CF in which intercore XT could be further suppressed.
