Interaction of waveguide and localized modes in a phononic crystalS. Benchabane1, A. Khelif1, A. Choujaa1, B. Djafari-Rouhani2 and V. Laude1
1 Département LPMO, Institut FEMTO-ST, CNRS UMR 6174, Université de Franche-Comté - 32 avenue de l'Observatoire, F-25044 Besançon cedex, France
2 Laboratoire de Dynamique et Structure des Matériaux Moléculaires, CNRS UMR 8024 Université de Lille I - F-59655 Villeneuve d'Ascq cedex, France
received 5 April 2005; accepted in final form 21 June 2005
published online 20 July 2005
The transmission properties of phononic crystal waveguides with grafted stub resonators were measured. The phononic crystal consists of a two-dimensional periodical array of steel rods immersed in water. Waveguides for acoustic waves are created by removing a line defect and stubs are formed by removing rods from the sidewalls of the waveguide. Depending on the stub geometry, definite wavelengths are reflected from the stub creating a one-dimensional bandgap within the waveguide transmission spectrum, the bandwidth of which can be controlled by arranging a proper sequence of stubs. These effects are interpreted as the interaction of propagating waveguide modes with localized stub resonances.
43.20.+g - General linear acoustics.
43.35.+d - Ultrasonics, quantum acoustics, and physical effects of sound.
63.20.-e - Phonons in crystal lattices.
© EDP Sciences 2005