Multimode silicon photonics, leveraging mode-division multiplexing technologies, offers significant potential to increase capacity of large-scale multiprocessing systems for on-chip optical interconnects. These technologies have implications not only for telecom and datacom applications, but also for cutting-edge fields such as quantum and nonlinear photonics. Thus, the development of compact, low-loss and low-crosstalk multimode devices, in particular mode exchangers, is crucial for effective on-chip mode manipulation. This work introduces a novel mode exchanger that exploits the properties of subwavelength grating metamaterials and symmetric Y-junctions, achieving low losses and crosstalk over a broad bandwidth and a compact size of only 6.5 µm × 2.6 µm. The integration of SWG nanostructures in our design enables precise control of mode exchange through different propagation constants in the arms and metamaterial, and takes advantage of dispersion engineering to broaden the operating bandwidth. Experimental characterization demonstrates, to the best of our knowledge, the broadest operational bandwidth covering from 1,420 nm to 1,620 nm, with measured losses as low as 0.5 dB and extinction ratios higher than 10 dB. Enhanced performance is achieved within a 149 nm bandwidth (1,471–1,620 nm), showing measured losses below 0.4 dB and extinction ratios greater than 18 dB.

中文翻译：

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基于亚波长Y形结的宽带模式交换器


多模硅光子学利用模分复用技术，为提高片上光学互连的大规模多处理系统的容量提供了巨大的潜力。这些技术不仅对电信和数据通信应用具有影响，而且对量子和非线性光子学等尖端领域也有影响。因此，开发紧凑、低损耗和低串扰的多模器件，特别是模式交换器，对于有效的片上模式操纵至关重要。这项工作介绍了一种新型模式交换器，它利用亚波长光栅超材料和对称 Y 结的特性，在宽带宽和仅 6.5 µm × 2.6 µm 的紧凑尺寸上实现低损耗和串扰。我们的设计中集成了 SWG 纳米结构，可以通过臂和超材料中的不同传播常数来精确控制模式交换，并利用色散工程来拓宽工作带宽。据我们所知，实验表征表明最宽的工作带宽覆盖 1,420 nm 至 1,620 nm，测得的损耗低至 0.5 dB，消光比高于 10 dB。在 149 nm 带宽（1,471–1,620 nm）内实现了增强的性能，测量损耗低于 0.4 dB，消光比大于 18 dB。