Creating a Nanoscale “Black Hole” to Trap Light by a Single Au Nanosphere in an All‐Dielectric Nanocavity

Abstract Efficient manipulation of visible light at the subwavelength scale is a crucial issue for realizing light‐on‐a‐chip technology and other nanophotonic applications. In the past decade, many demonstrations based on the surface plasmon resonance of noble metallic materials and the Mie resonance of all‐dielectric materials are made showing that visible light can be captured and concentrated in the nanoscale dimension. Here, a new kind of hybrid metal–dielectric nanostructure composed of a single gold nanosphere and an individual silicon carbide nanogroove is designed and fabricated to capture the visible light like a “black hole”. It is demonstrated that a large portion of the incoming light is scattered in the forward direction, with only a tiny fraction scattering in a broad spectral range in the backward direction owing to the destructive interference between the hybrid electric and magnetic modes in the system. Meanwhile, the absorption of the gold nanosphere contributes to the strongly suppressed backscattering. Based on the scattering anisotropy exhibited herein, this hybrid metal–dielectric nanostructure can act as a nanoscale light source or a nanoantenna on a photonic chip, making it promising for the creation of novel nanophotonic devices.