We proposed a two-mode fiber (TMF) design that can effectively reduce the mode overlap between LP01 and LP11 modes by using a W-shaped index profile core structure, which is a primary concern in uncoupled mode division multiplexing (MDM). TMF has a three-layered core structure; central circular core, inner cladding, and outer ring core. We confirmed that in an optimal structure the LP01 mode was highly confined to the central core while the LP11 mode was guided along the outer ring core to result in a minimum overlap integral. We used a full-vectorial finite element method to estimate effective index, differential group delay (DGD), confinement loss, chromatic dispersion, and mode overlap controlling the parameters of the W-shaped structure. The optimized W-profile fiber provided optical characteristics within the ITU-T recommended standards over the entire C+L band.
All Science Journal Classification (ASJC) codes
- Atomic and Molecular Physics, and Optics