We numerically reveal the feasibility of designing multi-core fibers (MCFs) with the simple step-index (SI) profile within the standard 125- μ m cladding diameter. We show that the standard cladding diameter enables us to incorporate five identical cores for C-band operation, and the number of cores can be further increased with the heterogeneous core arrangement. We then propose a novel method of allocating the non-identical cores in heterogeneous MCFs (Hetero-MCFs), where the crosstalk (XT) and critical bending radius ( R _pk ) are improved comparing to that of Hetero-MCFs designed by the conventional method. These new types of step-index MCFs (SI-MCFs) with standard cladding diameter have potential application in the space-division multiplexing (SDM) systems.

中文翻译：

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具有标准包层直径的异质阶跃多芯光纤中的新型纤芯分配

我们在数值上揭示了在标准 125- μ m 包层直径。我们表明，标准包层直径使我们能够为 C 波段操作合并五个相同的纤芯，并且可以通过异构纤芯排列进一步增加纤芯的数量。然后，我们提出了一种在异构 MCF（异质 MCF）中分配不同核心的新方法，其中串扰（XT）和临界弯曲半径（ R _pk ) 与通过传统方法设计的 Hetero-MCFs 相比有所改进。这些具有标准包层直径的新型阶跃折射率 MCF（SI-MCF）在空分复用（SDM）系统中具有潜在的应用。