We incorporate two major types of SDM fibers (i.e. few mode fibers and multicore fibers) in a micro-optic collimator assembly and realize fully integrated multiport SDM fiber components (e.g. $1\times 2$ and $2\times 2$ beam splitters). The device fabrication procedure for SDM fibers is similar to that for a standard single mode fiber, but more accurate fiber alignment (e.g. lateral positioning for few mode fiber components and rotational alignment for multicore fiber components) is required to achieve both low mode (core) dependent loss and/or low inter-modal (inter-core) crosstalk. A number of exemplary multiport SDM components are fabricated with low excess loss (1-2.2 dB), low mode (core) dependent loss (< 1 dB) and moderate crosstalk (< −32 dB for a multicore fiber splitter and < −6.5 dB for a few mode fiber splitter).

中文翻译：

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用于空分复用 (SDM) 系统的多端口光纤分束器

我们将两种主要类型的 SDM 光纤（即少模光纤和多芯光纤）集成到微光准直器组件中，并实现了完全集成的多端口 SDM 光纤组件（例如 $1\乘以2$ 和 $2\乘以 2$ 分束器）。SDM 光纤的设备制造程序与标准单模光纤的设备制造程序类似，但需要更精确的光纤对准（例如，少数模式光纤组件的横向定位和多芯光纤组件的旋转对准）以实现低模（芯）相关损耗和/或低模态间（核心间）串扰。许多示例性多端口 SDM 组件的制造具有低过量损耗 (1-2.2 dB)、低模式（芯）相关损耗 (< 1 dB) 和中等串扰（对于多芯光纤分路器来说 < -32 dB 和 < -6.5 dB用于少模光纤分路器）。