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arXiv · 2311.18272

Topological Directional Coupler

Yandong Li·Minwoo Jung·Yang Yu·Yuchen Han·Baile Zhang·Gennady Shvets
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Abstract

Interferometers and beam splitters are fundamental building blocks for photonic neuromorphic and quantum computing machinery. In waveguide-based photonic integrated circuits, beam-splitting is achieved with directional couplers that rely on transition regions where the waveguides are adiabatically bent to suppress back-reflection. We present a novel, compact approach to introducing guided mode coupling. By leveraging multimodal domain walls between microwave topological photonic crystals, we use the photonic-spin-conservation to suppress back-reflection while relaxing the topological protection of the valley degree of freedom to implement tunable beam splitting. Rapid advancements in chip-scale topological photonics suggest that the proposed simultaneous utilization of multiple topological degrees of freedom could benefit the development of novel photonic computing platforms.

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Yandong Li, Minwoo Jung, Yang Yu, Yuchen Han, Baile Zhang, Gennady Shvets. 2023-11-30. Topological Directional Coupler. https://arxiv.org/abs/2311.18272

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