Flexural wave splitting via elastic metagratings based on high-order diffraction theory

Wave splitting, one of the most valuable applications in wavefront modulation, is of great significance in both practical engineering and academia. However, to date, the available techniques to split waves are scarce aside from using conventional metasurfaces governed by the generalized Snell’s law. To this end, based on the newly proposed high-order diffraction theory, we design a type of simply structured elastic metagrating for the splitting of flexural waves in plate-like structures. Theoretical models are established to characterize wave propagation behavior in metagratings and functional units. Theoretical analysis confirms the validity of our designs, which is also supported by numerical simulations and experiments. The present study provides a general method for the designing of wave splitters.