Highly Sensitive, Affordable, and Adaptable Refractive Index Sensing with Silicon‐Based Dielectric Metasurfaces
Highly Sensitive, Affordable, and Adaptable Refractive Index Sensing with Silicon‐Based Dielectric Metasurfaces
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DOI：
10.1002/admt.201800567
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发表时间：
2018-12
影响因子：
6.8
通讯作者：
Adam J. Ollanik;Isaac O Oguntoye;George Z. Hartfield;M. Escarra
中科院分区：
文献类型：
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作者：
Adam J. Ollanik;Isaac O Oguntoye;George Z. Hartfield;M. Escarra
提出了一种利用介电惠更斯源超表面测量微流控通道折射率变化的传感平台，实验测量灵敏度为323 nm RIU−1，优值（FOM）为5.4，每折射率单位（T/RIU）透射率变化响应为8.2（820%）。通过单波长透射率测量可以测量流过通道的液体的折射率变化，只需要一个简单的光源和光电探测器，与最先进的折射率传感技术相比，显着降低了设备费用。一项技术经济分析预测，一种成本约为2400美元的设备能够检测到2*10−8量级的折射率变化。所使用的元表面是低调的，可扩展的，并且使用与CMOS和其他技术兼容的材料和制造工艺，使其适合器件集成。惠更斯超表面系统的特点是频谱重叠的电偶极子和磁偶极子模式，提供了高度的可定制性。两种共振之间的相互作用可以通过超表面几何来控制，从而导致器件灵敏度和测量范围的可调性。利用小入射角照射的惠更斯超表面的反对称共振，计算证明了350 nm RIU−1的超高灵敏度，FOM为219，对应于360 RIU−1的单波长灵敏度。
A sensing platform is presented that uses dielectric Huygens source metasurfaces to measure refractive index changes in a microfluidic channel with experimentally measured sensitivity of 323 nm RIU−1, a figure of merit (FOM) of 5.4, and a response of 8.2 (820%) change in transmittance per refractive index unit (T/RIU). Changes in the refractive index of liquids flown through the channel are measured by single‐wavelength transmittance measurement, requiring only a simple light source and photodetector, significantly reducing device expense in comparison to state‐of‐the‐art refractive index sensing technologies. A technoeconomic analysis predicts a device costing ≈$2400 that is capable of detecting refractive index changes of the order of 2*10−8. The metasurfaces utilized are low profile, scalable, and use materials and fabrication processes compatible with CMOS and other technologies making them suitable for device integration. The Huygens metasurface system, characterized by spectrally overlapping electric and magnetic dipole modes, offers a high degree of customizability. Interplay between the two resonances may be controlled via metasurface geometry, leading to tunability of device sensitivity and measurement range. Ultrahigh sensitivity of 350 nm RIU−1 with FOM of 219, corresponding to single‐wavelength sensitivity of 360 RIU−1, is demonstrated computationally through use of antisymmetric resonances of a Huygens metasurface illuminated at small incidence angles.