Sharp Fano resonance induced by all-dielectric asymmetric metasurface

摘要

Plasmonic metasurfaces have attracted tremendous attentions due to the broad applications in chemical and biomedical sensing, surface enhanced spectroscopy, and near-field scanning optical microscopy. However, it is still a great challenge to enhance the figure of merit and sensitivity of sensors in near-infrared wavelengths due to the inherent resistive loss of conventionally used metallic materials. In this paper, we designed an all-dielectric metasurface composed of asymmetric double nanorods to achieve ultra-narrow band Fano resonance. Benefitting from the interference of bright mode and dark mode, a sharp and wavelength-adjustable reflectance peak can be obtained, offering an excellent platform for biological sensing and detection.