Ultra-narrow Band Perfect Absorber and Its Application as Plasmonic Sensor in the Visible Region

Nanoscale Research Letters

Han Ye¹  Li Yu¹  Lei Chen¹  Chang Liu¹  Rui Ma¹  Ruifang Li¹  Dong Wu¹  Yumin Liu¹  Zhongyuan Yu¹ 

[1] State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications;

关键词: Metamaterial;    Absorber;    Ultra-narrowband;    Plasmonics;    Sensing;    FDTD;   

DOI  :  10.1186/s11671-017-2203-9

来源: DOAJ

【 摘 要 】

Abstract We propose and numerically investigate a perfect ultra-narrowband absorber with an absorption bandwidth of only 1.82 nm and an absorption efficiency exceeding 95% in the visible region. We demonstrate that the perfect ultra-narrowband absorption is ascribed to the coupling effect induced by localized surface plasmon resonance. The influence of structural dimensions on the optical performance is also investigated, and the optimal structure is obtained with the extremely low reflectivity (0.001) of the resonance dip. The perfect absorber can be operated as a refractive index sensor with a sensitivity of around 425 nm/RIU and the figure of merit (FOM) reaching 233.5, which greatly improves the accuracy of the plasmonic sensors in visible region. Moreover, the corresponding figure of merit (FOM*) for this sensor is also calculated to describe the performance of the intensity change detection at a fixed frequency, which can be up to 1.4 × 105. Due to the high sensing performance, the metamaterial structure has great potential in the biological binding, integrated photodetectors, chemical applications and so on.

【 授权许可】

Unknown