Anomalous deflecting of high frequency SH wave by waveguides with phase discontinuities using different order guided wave modes

Abstract

The generalized Snell's law (GSL) with phase discontinuity proposed based on the concept of a metasurface, which can be used to control arbitrarily the reflection and refraction of waves, attracts a growing attention in these years. The concept of abnormally deflecting the incident wave has been applied to the elastic field by researchers very recently. Here, we extend the concept of acoustic metasurface to the elastic meta-slab composed by waveguides with the same kind material for high frequency SH wave. The waveguides are assumed to be applied anti-symmetric and symmetric boundary conditions and the length of the waveguides are designed based on the GSL, which makes the meta-slab give abnormal refraction for the incident wave. The finite element method is employed to do the full wave simulation to confirm the abnormal deflecting of the incident wave. It is found that different phase velocities of the corresponding wave modes can be utilized to construct the meta-slab with phase discontinuities to abnormally deflect the incident wave.