Interaction of waveguide and localized modes in a phononic crystal

International audienceThe transmission properties ofphononic crystal waveguides with grafted stub resonators were measured. The phononic crystal consists of a two-dimensional periodical array ofsteel 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 ofwhich can be controlled by arranging a proper sequence ofstubs. These effects are interpreted as the interaction ofpropagating waveguide modes with localized stub resonances