Surface corrugated laminates as elastic grating couplers: Splitting of SV- and P-waves by selective diffraction

Abstract

The phenomenon of selective diffraction is extended to in-plane elastic waves, and we design surface corrugated periodic laminates that incorporate crystal momentum transfer, which, due to the rich physics embedded within the vector elastic system, results in frequency, angle, and wave-type selective diffraction. The resulting devices are elastic grating couplers, with additional capabilities as compared to analogous scalar electromagnetic couplers, in that the elastic couplers possess the ability to split and independently redirect, through selective negative refraction, the two body waves present in the vector elastic system: P- (compressional) and SV- (shear-vertical) elastic waves. The design paradigm, and interpretation, is aided by obtaining isofrequency contours via a non-dimensionalized transfer matrix method.

The Elastic Spiral Phase Pipe

“…Advances in computational linear algebra allow this with ease [70], and have advantages over other matrix methods susceptible to the so called large f-d problem (e.g. the transfer matric method (TMM) and global matrix formalism [71,72,73,74,75]).…”