Omnidirectional reflection control of plane waves via giant magnetostrictive materials

The omnidirectional reflection behaviors of elastic waves and tuned by external magnetic fields are investigated in this paper. The projected band structures are used for analyzing omnidirectional reflection bands, which are also validated by the refraction spectra. It is demonstrated that the omnidirectional reflection phenomenon can be efficiently tuned via the external magnetic field imposed on the Terfenol-D layer. Furthermore, an absolute band gap can be achieved by constructing two superlattices in tandem with different magnetic fields. Our design scheme and the modulation methodology open a new prospect for designing active acoustic mirrors and filters with high quality.