Nature Communications ( IF 14.7 ) Pub Date : 2023-09-27 , DOI: 10.1038/s41467-023-41068-1
Tiancheng Zhang 1 , Kaichen Dong 2, 3, 4, 5, 6 , Jiachen Li 1, 3 , Fanhao Meng 1, 3 , Jingang Li 7 , Sai Munagavalasa 8 , Costas P Grigoropoulos 7 , Junqiao Wu 1, 2, 3 , Jie Yao 1, 2, 3
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The twisted stacking of two layered crystals has led to the emerging moiré physics as well as intriguing chiral phenomena such as chiral phonon and photon generation. In this work, we identified and theoretically formulated a non-trivial twist-enabled coupling mechanism in twisted bilayer photonic crystal (TBPC), which connects the bound state in the continuum (BIC) mode to the free space through the twist-enabled channel. Moreover, the radiation from TBPC hosts an optical vortex in the far field with both odd and even topological orders. We quantitatively analyzed the twist-enabled coupling between the BIC mode and other non-local modes in the photonic crystals, giving rise to radiation carrying orbital angular momentum. The optical vortex generation is robust against geometric disturbance, making TBPC a promising platform for well-defined vortex generation. As a result, TBPCs not only provide a new approach to manipulating the angular momentum of photons, but may also enable novel applications in integrated optical information processing and optical tweezers. Our work broadens the field of moiré photonics and paves the way toward the novel application of moiré physics.
中文翻译:
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扭曲莫尔光子晶体能够通过连续体中的束缚态产生光学涡旋
两层晶体的扭曲堆叠导致了新兴的莫尔物理以及有趣的手性现象,例如手性声子和光子生成。在这项工作中,我们在扭曲双层光子晶体(TBPC)中确定并从理论上阐述了一种非平凡的扭曲启用耦合机制,该机制通过扭曲启用通道将连续介质(BIC)模式中的束缚态连接到自由空间。此外,TBPC 的辐射在远场具有奇数和偶数拓扑序的光学涡旋。我们定量分析了光子晶体中 BIC 模式和其他非局域模式之间的扭转耦合,从而产生携带轨道角动量的辐射。光学涡旋生成对于几何扰动具有鲁棒性,使 TBPC 成为良好定义的涡旋生成的有前途的平台。因此,TBPC不仅提供了一种操纵光子角动量的新方法,而且还可能在集成光学信息处理和光镊中实现新的应用。我们的工作拓宽了莫尔光子学领域,并为莫尔物理学的新颖应用铺平了道路。