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，设计并制作了一种由金属涂层纳米翅片组成的三维悬浮纳米翅片空腔结构。由于等离子体热点与纳米翅片腔的耦合，在纳米翅片腔中维持了在环路中转向光的强光流，纳米翅片腔结构的光学性质在共振波长下从高透明变为高反射。因此，在从近红外区到红外区的很宽的范围内实现了强的、可调的反射共振。通过改变纳米鳍腔的周期可以调谐较强的反射带，这为利用悬浮的纳米鳍腔结构利用微系统操纵纳米鳍腔提供了一种很有前途的方法。综上所述，由于SPR的严格条件，产生了强而窄带的反射共振，从近红外到红外区使用不同的阶模，具有92 nm的半高宽和高达60的质量因子，并且还可以通过改变纳米翅的周期来调节。虽然这项研究主要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，但纳米鳍腔结构可以设计成满足从可见光到太赫兹区域的许多其他应用的要求。纳米鳍腔结构的特点为设计带通滤光器、光开关、传感器以及在指纹领域的应用提供了新的途径。

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.