On a Scalable Path for Multimode SDM Transmission
On a Scalable Path for Multimode SDM Transmission
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DOI：
10.1109/jlt.2023.3308777
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发表时间：
2024-01
影响因子：
4.7
通讯作者：
F. A. Barbosa;Filipe M. Ferreira
中科院分区：
文献类型：
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作者：
F. A. Barbosa;Filipe M. Ferreira
我们研究了多模光纤上空间复用传输的收发器设计和数字信号处理。在传统架构中，必须检测和处理传输光纤的整个空间域，使得可以估计和均衡模式走离和混合。这些架构的规模与所支持的模式的数量差，除了光纤传输矩阵的稀疏性没有得到充分利用。相反，在这里，我们的目标是采用选择性模式矢量发射和检测，以尽量减少所需的光学前端的数量。在这种情况下，多路复用的理想基础是由主模式提供的，其第一阶是频率无关的。我们表明，这种模式矢量的基础上，可以用于全波特率传输数据中心间的距离，尽管有限的相干带宽和脆弱性环境引起的漂移的光通道。结果表明，在接收器前端的串扰可以显着抑制，关键减少相干接收器前端的数量，旨在数据传输的空间支流-而不是光纤模式的总数。由于环境引起的信道漂移和存在模式相关损耗时的正交性损失，仍然会出现残余串扰。多输入单输出数字信号处理被证明是有效的，在这种情况下，与所需的均衡器阵列的大小缩放次线性与支流的数量。考虑了一种具有156个空间和偏振模并针对低模色散进行了优化的多模光纤。
We investigate transceiver design and digital signal processing for spatially multiplexed transmission over multimode fibers. In conventional architectures, the full spatial domain of the transmission fiber has to be detected and processed such that the modal walk-off and mixture can be estimated and equalized. These architectures scale poorly with the number of modes supported, besides the sparsity of the fiber transfer matrix is not fully exploited. Instead, here we aim to employ selective mode vector launch and detection in order to minimize the number of optical front-ends required. In this case, an ideal basis for multiplexing is offered by principal modes, that to first order are frequency independent. We show that such mode vector basis can be used for full baud rate transmission over inter-data center distances despite limited coherence bandwidth and vulnerability to environmental-induced drift of the optical channel. It is shown that crosstalk at the receiver front-end can be significantly suppressed, critically reducing the number of coherent receiver front-ends to that of spatial tributaries aimed for data transmission – as opposed to the total number of fiber modes. Residual crosstalk can still be experienced due to environmental-induced channel drift and loss of orthogonality in presence of mode dependent loss. Multiple-input single-output digital signal processing is shown to be effective in this case, with the required equalizer array size scaling sub-linearly with the number of tributaries. A multimode fiber with 156 spatial and polarization modes and optimized for low modal dispersion is considered.