Design of highly-elliptical-core ten-mode fiber for space division multiplexing with 2x2 MIM

We propose a weakly-coupled few-mode fiber requiring only 2×2 MIMO equalizer blocks, which makes it compatible with standard coherent receivers with polarization diversity. The fiber has a highly-elliptical core, surrounded by a depressed index trench in the cladding, and supports five spatial modes with twofold polarization degeneracy (ten channels). The fiber is designed to mitigate inter-modal crosstalk since the effective index difference between spatial modes is larger than ∼1×10−3 over the C-band. Through numerical simulations, we report on bending loss and other modal characteristics such as effective area and chromatic dispersion. Finally, we briefly discuss the scalability of the design