Watanabe Tatsuhiko, Kokubun Yasuo
Opt Express. 2014 Apr 7;22(7):8309-19. doi: 10.1364/OE.22.008309.
The ultimate number of transmission channels in a fiber for the space division multiplexing (SDM) is shown by designing an air-hole-assisted double-cladding few-mode multi-core fiber. The propagation characteristics such as the dispersion and the mode field diameter are almost equalized for all cores owing to the double cladding structure, and the crosstalk between adjacent cores is extremely suppressed by the heterogeneous arrangement of cores and the air holes surrounding the cores. Optimizing the structure of the air-hole-assisted double-cladding, ultra dense core arrangements, e.g. 129 cores in a core accommodated area with 200 μm diameter, can be realized with low crosstalk of less than -34.3 dB at 100km transmission. In this design, each core supports 3 modes i.e. LP(01), LP(11a), and LP(11b) as the transmission channels, so that the number of transmission channels can be 3-hold greater than the number of cores. Therefore, 387 transmission channels can be realized.
通过设计一种气孔辅助双包层少模多芯光纤，展示了用于空分复用（SDM）的光纤中传输通道的最终数量。由于双包层结构，所有芯的色散和模场直径等传播特性几乎得到均衡，并且通过芯的异质排列以及围绕芯的气孔，相邻芯之间的串扰得到极大抑制。通过优化气孔辅助双包层的结构，可以实现超密集的芯排列，例如在直径为200μm的芯容纳区域中有129个芯，在100km传输时串扰低于-34.3dB。在这种设计中，每个芯支持3种模式，即LP(01)、LP(11a)和LP(11b)作为传输通道，因此传输通道的数量可以比芯的数量大三倍。因此，可以实现387个传输通道。
