高品质因子亚波长介质纳米柱的演示
Demonstration of a High-Q Subwavelength Dielectric Nanocylinder
AI总结：
本研究利用连续介质中的束缚态（BIC），研制出Q值超1000的超小尺寸磷化铟亚波长纳米柱，为高性能小型光子器件提供了新方案。
AI中文摘要：
亚波长介质腔的开发对于减小光子器件尺寸、实现密集成光电子集成至关重要。然而，此前的亚波长光学腔的品质因子（Q值）均小于400，限制了其应用。本研究利用连续介质中的束缚态（BIC），演示了一种高品质因子的亚波长纳米柱，在保持超小 footprint 的同时追踪不同纵向阶次的BIC模式，发现Q值先上升后在高阶次趋于饱和。通过将准正常模微扰理论与耦合模分析相结合，揭示了该饱和的物理起源，并确定了平衡性能与制造可行性的优化尺寸。通过使用纳米桥将该设计悬浮于自由空间并优化纳米制造工艺，实验实现了Q值实测超过1000的磷化铟（InP）亚波长纳米柱。与低Q值的衬底支撑对应结构相比，悬浮的高Q BIC纳米柱表现出更强的散射和光致发光信号。本研究为超小 footprint 的高Q光学器件提供了一条可行路径。
英文摘要：
The development of subwavelength dielectric cavities is essential for reducing the size of photonic devices and enabling dense optoelectronic integration. However, previouslysubwavelengthoptical cavities exhibit demonstrated Q-factors <400, limiting their applications. Here, we demonstrate a high-Q subwavelength nanocylinder by leveraging bound states in the continuum (BIC). We track BIC modes of different longitudinal orders while maintaining an ultrasmall footprint. We find that the Q-factor initially increases but then saturates at higher orders. By linking quasi-normal-mode perturbation theory with coupled-mode analysis, we reveal the physical origin of this saturation and identify an optimized dimension that balances performance with fabrication feasibility. By suspending this design in free space using nanobridges and optimizing the nanofabrication process, we experimentally realize an InP subwavelength nanocylinder with a measured Q-factor exceeding 1000. Compared with a lower-Q substrate-supported counterpart, the suspended high-Q BIC nanocylinder exhibits stronger scattering and photoluminescence signals. Our work provides a route to high-Q optical devices with ultrasmall footprints.
