High-Q All-Dielectric Metasurface: Super and Suppressed Optical Absorption

• DOI: 10.1021/acsphotonics.0c00003
• Publication Date: 2020-04-29T20:01:26Z
• Authors: Jingyi Tian; Qiang Li; Pavel A Belov; Ravindra Kumar Sinha; Weiping Qian; Min Qiu
• Keywords: Q factor

All-dielectric metasurface absorbers are good candidates for realizing near-unity light absorption within subwavelength-thin nanostructures. However, only moderate quality factor (Q-factor, e.g., Q ∼ 10) all-dielectric have been demonstrated due to high radiative loss of the supported Mie resonances. Here, we theoretically propose a high-Q crystalline silicon superabsorber with in near-infrared region by utilizing dipole quasi bound states continuum (quasi-BIC) resonances engineered loss. The designed shows (∼640) region. Moreover, when superstrate refractive index is different from that substrate, anticrossing behavior induced quasi-BIC can be observed spectra. This design applies arbitrary high-refractive-index low-loss materials at various working bands, enabling practical applications ultrathin superabsorbers optical sensing, filtering, and photon detection.