Abstract
In this paper, we study the polarization states of the localized sagittal modes in a solid/solid one-dimensional phononic crystal with a defect layer. We have found that the well defined polarization of these modes, either transverse or longitudinal, for propagation in the direction of periodicity is completely modified for the case of oblique propagation. Thus for practical applications the polarization-the transverse/longitudinal component rate-of the defect modes will depend on the angle of incidence. For calculations, we use the supercell method; the criterion of energy balance is employed to determine the polarization state of all the acoustic waves. The results show the existence of localized elastic modes in the band gaps and resonant vibrations inside the allowed bands. By analyzing the amplitude profiles, we conclude that the displacement localization of both transverse and longitudinal components can be different. Consequently, the polarization of the transmission peaks could depend on the thickness of the sample. The interesting effect of change in polarization (from quasitransverse to quasilongitudinal) of some transmission peaks as function of the angle of incidence is reported. Calculations were made for an Epoxy/Sn superlattice with Zn as defect layer.
Original language | English |
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Article number | 033515 |
Journal | Journal of Applied Physics |
Volume | 107 |
Issue number | 3 |
DOIs | |
State | Published - 2010 |