Low-reflection beam refractions by ultrathin Huygens metasurface

Manipulating acoustic wave reflection by a nonlinear elastic metasurface

Specular Reflection Reduction by Metasurface based on Parameteradjustable Meta-Atoms

Ultrathin four-reflection imager.

We present the design and experimental demonstration of an ultrathin four-reflection imager. The F/1.15 prototype imager achieves a focal length of 18.6 mm in a track length of just 5.5 mm, providing a 17 degrees field of view over 1.92 megapixels of a color image sensor with 3 microm pixels. We also present the design and experimental results of pupil-phase encoding and postprocessing, which w...

Generalized Huygens principle with pulsed-beam wavelets

Huygens’ principle states that the solution of the wave equation radiated by a bounded source can be represented outside the source region as a superposition of spherical ‘Huygens wavelets’ radiated by secondary point-sources on a surface enclosing the primary source. This was originally proposed as a geometrical explanation of wave propagation, but as such it is conceptually problematic becaus...

Acoustic carpet cloak based on an ultrathin metasurface

An acoustic metasurface carpet cloak based on membrane-capped cavities is proposed and investigated numerically. This design has been chosen for allowing ultrathin geometries, although adapted to airborne sound frequencies in the range of 1 kHz (λ ≈ 30 cm), surpassing the designs reported in the literature in terms of thinness. A formulation of generalized Snell’s laws is first proposed, mappin...