Ultra-Low Crosstalk Multi-core Fiber with Standard 125-μm Cladding Diameter for 10,000 km-class Long-haul Transmission

Abstract

We propose an ultra-low inter-core crosstalk (XT) multi-core 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 fabricating the MCF is feasible along with long-distance transmission by confirming the that the XT noise performance corresponds to transmission distances of 10,000 km or more.