高アスペクト比キャビティ内への閉じ込め効果を用いた高感度バイオマーカー検出手法

在本研究中，我们设计并制作了一个由金属包覆的纳米鳍所组成的三维悬浮式纳米鳍腔结构。由于等离子体激元热点与纳米鳍腔的耦合，在纳米鳍腔中维持使光在回路中转向的强光流，并且纳米鳍腔结构的光学性质在谐振波长处从高度透明变为高度反射。因此，在从NIR到IR区域的非常宽的范围内实现了强且可调谐的反射共振。强反射带可以通过改变纳米鳍腔的周期来调谐，并且这提出了一种通过利用悬浮纳米鳍腔结构的微系统来操纵纳米鳍腔的有希望的方式。总之，由于SPR的严格条件而产生的强且窄带的反射率共振，其带宽具有92nm的半峰全宽和从NIR到IR区域的高达60的品质因数，使用不同的阶次模式以及通过改变纳米鳍的周期的可调谐性。虽然这项研究集中在红外和近红外区域的滤波和开关特性，这是研究指纹区域和生物传感的主要兴趣，纳米鳍腔结构可以被设计为适应许多其他应用的要求，在可见光的太赫兹区域。纳米鳍腔结构的特性为带通滤波器、光开关、传感器以及指纹领域的应用提供了新的思路。

In this research, a three-dimensional suspended nanofin-cavity structure consisting of metal-coated nanofins was designed and fabricated. Due to the coupling of plasmonic hot spots to the nanofin-cavities, strong optical flows turning light in a loop are sustained in the nanofin cavities and the optical properties of the nanofin-cavity structure change from being highly transparent to highly reflective at the resonance wavelength. Therefore, strong and tunable reflected resonances are realized in a very wide range from the NIR to IR region. A strong reflectance band can be tuned by varying the period of the nanofin cavities, and this presents a promising way to manipulate the nanofin cavities through the use of microsystems taking advantage of the suspended nanofin-cavity structure. In summary, a strong and narrow-band reflectance resonance due to the stringent condition of SPR arises with a bandwidth having a full width at half-maximum of 92 nm and a quality factor as large as 60 from the NIR to IR region using different order modes and also tunability by varying the period of the nanofins. Although this study concentrated on the filtering and switching properties in the IR and NIR region, which are of major interest for studying the fingerprint region and biosensing, the nanofin-cavity structure can be designed to suit the requirements of many other applications in the visible to the terahertz regions. The characteristics of the nanofin-cavity structure provide a new way to design band-pass filters, optical switches, sensor, and applications in the fingerprint region.