Double-layered metal grating for high-performance refractive index sensing
Double-layered metal grating for high-performance refractive index sensing
复制标题
用于高性能折射率传感的双层金属光栅
DOI：
10.1364/oe.23.008995
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发表时间：
2015-04-06
期刊：
影响因子：
3.8
通讯作者：
Jin, Chongjun
中科院分区：
文献类型：
--
作者：
Li, Guozhen;Shen, Yang;Jin, Chongjun
通过金属纳米结构携带的局部表面等离子体共振（LSPR）检测局部折射率的微小变化已成功地用于诸如分子结合事件的实时和无标记检测的应用中。然而，局域等离子体激元表现出1-2个数量级的品质因数（FOM）相比，他们的传播同行。在这里，我们提出并实验证明了一种高性能的折射率传感器的基础上的结构的双层金属光栅（DMG）的FOM和FOM* 分别达到38和40的垂直入射下。如此高的FOM和FOM* 是由尖锐的法诺共振的结果引起的，该共振是由来自各个顶部金条纹的LSPR与伍德异常（WA）之间的相干干涉引起的。此外，在DMG中确定了类似于68 nm的小的共形衰减长度，表明DMG是无标记生物医学传感的有希望的候选者。(C)2015美国光学学会
The detection of minuscule changes in the local refractive index by localized surface plasmon resonances (LSPRs), carried by metal nanostructures, has been used successfully in applications such as real-time and label-free detection of molecular binding events. However, localized plasmons demonstrate 1-2 orders of magnitude lower figure of merit (FOM) compared with their propagating counterparts. Here, we propose and experimentally demonstrate a high-performance refractive index sensor based on a structure of double-layered metal grating (DMG) with an FOM and FOM* reaching 38 and 40 respectively under normal incidence. Such a high FOM and FOM* arise from a result of a sharp fano resonance, which is caused by the coherent interference between the LSPR from the individual top gold stripes and Wood's anomaly (WA). Moreover, a small conformal decay length of similar to 68 nm is determined in DMG, indicating that the DMG is a promising candidate for label-free biomedical sensing. (C) 2015 Optical Society of America