High-density 4-core MCF with 160-µm-coating for 1.31µm-wavelength IMDD and 1.55µm-wavelength WDM transmissions

Space-division multiplexing (SDM) via multi-core fibers (MCFs) offers a route to increase optical link capacity. We describe 4-core MCFs utilizing a trench core profile with 100 µm-cladding and 160 µm-coating, achieving a core density of approximately 10 times that of a standard 125 µm-cladding, 250 µm-coated single-core fiber. The attenuation at 1310 and 1550 nm is within the ITU-T G.652.D limits. The 1-km inter-core crosstalk is -40 dB/km or less compared with that of conventional 4-core MCFs with a step-index core. Compared with a standard diameter design, this fiber enables a reduced cable diameter without compromising performance, delivering compact and high-density cables for connections within and between data centers.