Quasi-bound states in the continuum (quasi-BIC) are a particular resonant state, which can be regulated by the degree of symmetry breaking in nanostructures. Here, we propose a fourfold rotationally symmetric (C 4v ) metasurface supporting the dual quasi-BIC modes. The Fano characteristics have observed in the near-infrared region. The resonant peaks of the dual quasi-BIC modes can be adjusted flexibly and independently with a simple breaking of the structural symmetry. More importantly, the dual quasi-BIC modes demonstrate the extraordinary capability in controlling the optical activity. This work will offer us more freedom for controlling the resonance and optical activity by the quasi-BIC modes, which is promising to engineer the optical device in displaying and optics communications.

中文翻译：

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用于光学活动操纵的连续模式中的双准束缚态


连续体中的准束缚态（准BIC）是一种特殊的共振态，可以通过纳米结构中对称性破缺的程度来调节。在这里，我们提出了一种支持双准 BIC 模式的四重旋转对称 (C 4v ) 超表面。在近红外区域观察到法诺特征。通过简单地破坏结构对称性，可以灵活、独立地调节双准BIC模式的谐振峰。更重要的是，双准BIC模式展示了控制光学活性的非凡能力。这项工作将为我们通过准 BIC 模式控制谐振和光学活动提供更多自由，这有望用于设计显示和光学通信中的光学器件。