Abstract The mode-division (de) multiplexing (MDM) technology is promising to scale the transmission capacity of on-chip optical communications by carrying information on different spatial modes of a multimode waveguide. For the current MDM technology, different spatial modes are first converted to the fundamental mode and then modulated in parallel by individual electro-optic modulators, which may result in a large device footprint and high-power consumption. Here we designed a graphene-based silicon nitride waveguide-integrated spatial mode modulator to individually modulate different spatial modes in a multimode waveguide. Specifically, we utilized the coplanar interaction between patterned graphene layers and propagating light in the multimode waveguide to introduce contrasting phase shifts to different spatial modes. Based on the optimized waveguide configuration, a Mach–Zehnder interferometer modulator is designed. Our study paves the way for the development of high-density on-chip MDM systems for optical interconnects and on-chip optical networks.

中文翻译：

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石墨烯基氮化硅多模波导集成电光调制器的设计

摘要 模分复用（MDM）技术有望通过承载多模波导不同空间模式的信息来扩展片上光通信的传输容量。对于当前的 MDM 技术，首先将不同的空间模式转换为基模，然后由单独的电光调制器并行调制，这可能导致器件占用空间大和功耗高。在这里，我们设计了一种基于石墨烯的氮化硅波导集成空间模式调制器，以单独调制多模波导中的不同空间模式。具体来说，我们利用图案化石墨烯层与多模波导中传播光之间的共面相互作用，将对比相移引入不同的空间模式。基于优化的波导配置，设计了 Mach-Zehnder 干涉仪调制器。我们的研究为开发用于光互连和片上光网络的高密度片上 MDM 系统铺平了道路。