We present a novel 21-core homogeneous multi-core fiber (MCF) structure with three different types of core placement layouts (1-Ring, 2-Ring, and Square Lattice) and densely pack the cores with a minimum cladding diameter of 200 μm to support high-speed applications. In the first phase, three MCF structures (1-Ring, 2-Ring, and Square Lattice) were designed with a step refractive index (RI) profile under the limited cladding thickness and diameter of 35 and 200 μm, respectively, and their crosstalk was calculated. In the second phase, all three structures were designed with a low-RI trench-assisted (TA) profile to significantly reduce the crosstalk. To further suppress the crosstalk, air holes were placed between the TA cores, and it was found that the TA Square Lattice core arrangement with air holes achieved the minimum crosstalk value of approximately −70 dB / 100 km. The impact of important design parameters, such as transmission distance, bending radius, operating wavelength, and core diameter on inter-core crosstalk for all three design structures for both RI profiles and air-hole arrangement were numerically analyzed. Furthermore, other transmission characteristics, such as group delay and dispersion concerning wavelength, were analyzed for the above-stated design structures.

中文翻译：

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用于高速光通信的21芯沟槽和气孔辅助多芯光纤设计

我们提出了一种新颖的 21 芯同质多芯光纤 (MCF) 结构，具有三种不同类型的纤芯布局布局（1 环、2 环和方形晶格），并以最小包层直径为 200 μm 密集封装纤芯以支持高速应用。在第一阶段，设计了三种 MCF 结构（1-Ring、2-Ring 和 Square Lattice），在有限的包层厚度和直径分别为 35 和 200 μm 以及它们的串扰下具有阶跃折射率（RI）分布被计算。在第二阶段，所有三种结构均采用低 RI 沟槽辅助 (TA) 剖面设计，以显着降低串扰。为了进一步抑制串扰，在 TA 磁芯之间放置了气孔，并且发现带有气孔的 TA Square Lattice 纤芯排列实现了大约 -70 dB / 100 km 的最小串扰值。数值分析了传输距离、弯曲半径、工作波长和纤芯直径等重要设计参数对 RI 剖面和气孔排列的所有三种设计结构的纤芯间串扰的影响。此外，针对上述设计结构分析了其他传输特性，例如与波长相关的群延迟和色散。