Sato Rodrigo, Vinther Bertelsen Christian, Nikitin Maxim, Lopez Aymerich Elena, Malureanu Radu, Edith Svendsen Winnie, Lavrinenko Andrei V, Takayama Osamu
DTU Electro, Technical University of Denmark, Ørsteds Plads, Building 343, DK-2800, Kgs. Lyngby, Denmark.
DTU Bioengineering - Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads, Building 221, DK-2800, Kgs. Lyngby, Denmark.
Nat Commun. 2024 Dec 4;15(1):10544. doi: 10.1038/s41467-024-54929-0.
Bound states in the continuum are optical modes with extremely high-quality factors and narrow resonances, which exist in the dispersion spectrum of the radiative region above the light line. A unique bound state in the continuum is supported at the edge of truncated photonic crystals, which is a type of a Fabry-Pérot type bound state in the continuum, but has never been observed in experiments. Here, we demonstrate the bound states in the continuum supported at the edge array of silicon (Si) pillars whose diameter is bigger than that of the rest of a Si-pillar two-dimensional photonic crystal. We also show the tunability of the resonance and surface sensitivity of the mode when Si pillars are conformally coated with nanometer-thick aluminium oxide films. The presence of an oxide nanofilm improves the quality factor by over 60 % and shifts the resonance wavelength. Such behavior signifies the substantial potential of the bound states in the continuum on two-dimensional photonic crystals for post-fabrication tuning of the quality factor and surface sensing applications.
连续谱束缚态是具有极高品质因数和窄共振的光学模式，存在于光线上方辐射区域的色散谱中。在截断光子晶体的边缘支持一种独特的连续谱束缚态，它是法布里 - 珀罗型连续谱束缚态的一种，但从未在实验中被观测到。在此，我们展示了在直径大于二维硅柱光子晶体其余部分的硅柱边缘阵列处支持的连续谱束缚态。我们还展示了当硅柱被纳米厚的氧化铝膜共形包覆时，该模式的共振可调性和表面灵敏度。氧化物纳米膜的存在使品质因数提高了60%以上，并使共振波长发生偏移。这种行为表明二维光子晶体上的连续谱束缚态在品质因数的后制备调谐和表面传感应用方面具有巨大潜力。
