title: Shear Bloch waves and coupled phonon-polariton in periodic piezoelectric waveguides.
abstract: Coupled electro-elastic SH waves propagating in a periodic piezoelectric finite-width waveguide are considered in the framework of the full system of Maxwell's electrodynamic equations. We investigate Bloch-Floquet waves under homogeneous or alternating boundary conditions for the elastic and electromagnetic fields along the guide walls. Zero frequency stop bands, trapped modes as well as some anomalous features due to piezoelectricity are identified. For mixed boundary conditions, by modulating the ratio of the length of the unit cell to the width of the waveguide, the minimum widths of the stop bands can be moved to the middle of the Brillouin zone. The dispersion equation has been investigated also for phonon-polariton band gaps. It is shown that for waveguides at acoustic frequencies, acousto-optic coupling gives rise to polariton behavior at wavelengths much larger than the length of the unit cell but at optical frequencies polariton resonance occurs at wavelengths comparable with the period of the waveguide.
authors.affiliation: Department of Dynamics of Deformable Systems and Coupled Fields, Institute of Mechanics, Bagramyan ave 24B, Yerevan 0019, Armenia.
authors.forename: D G
authors.initials: DG
authors.lastname: Piliposyan
authors.forename: K B
authors.initials: KB
authors.lastname: Ghazaryan
authors.forename: G T
authors.initials: GT
authors.lastname: Piliposian
mesh_terms: D003198:Computer Simulation; D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D055617:Micro-Electrical-Mechanical Systems / Q000295:instrumentation*; D008962:Models, Theoretical; D012542:Scattering, Radiation; D013016:Sound; D014159:Transducers
keywords: Bang gaps; Floquet theory; Phonon–polariton; Piezoelectric phononic crystal