Design of 100-μm-cladding weakly coupled 4-core multi-core fiber with 160-μm-coating

Weakly coupled 4-core multi-core fiber (4c-MCF) with 125-μm cladding have been in standardization efforts. Compared with standard single-core fiber with 250-μm-coating, the 4c-MCF has a 4~6.25 times higher core density. In this study, we propose the possibility of a small cladding weakly coupled 4c-MCF, that can achieve approximately 10 times the core density. The feasibility of a 100-μm-cladding / 160-μm-coating 4c-MCF in 1.31-μm-wavelength was confirmed through simulations. The effective trench volume that can suppress confinement loss and XT were estimated, and confirmed that the propagation loss is similar to that of conventional 4c-MCF.