Ultra-low crosstalk multi-core fiber with standard 125-μm cladding diameter for 10,000km-class long-haul transmission

Abstract

We propose an ultra-low inter-core crosstalk (XT) multicore fiber (MCF) with standard 125-μm cladding. We show the fiber design and fabrication results of an MCF housing four cores with W-shaped index profile; it offers XT of less than -67 dB/km over the whole C+L band. This enables us to realize 10,000-km transmission with negligible XT penalty. We also observe a low-loss of 0.17 dB/km (average) at a wavelength of 1.55 μm and other optical properties compatible with ITU-T G.654.B fiber. We also elucidate its good micro-bend resistance in terms of both the loss and XT to confirm its applicability to high-density optical fiber cables. Finally, we show that the fabricated MCF is feasible along with long-distance transmission by confirming that the XT noise performance corresponds to transmission distances of 10,000 km or more.