Cladding-Rods-Assisted Depressed-Core 9-LP-Mode Fiber with Improved Modal Spacing

We report the design of a cladding-rods-assisted depressed-core 9-LP-mode fiber featuring more equally spaced modal effective indices, suitable for high-spatial-density uncoupled mode-division-multiplexing systems. It exhibits improved modal spacing (≥1.0×10
^-3
) and large modal effective areas (≥127 μm
²
).