Figure 1

Acoustic transmission and distribution of the displacement field for the periodic case, sample 1. (Top) Scheme of the periodic structure consisting of 12.5 periods of layers a and b. (Middle) Acoustic transmission spectra, measured in solid line and calculated in dashed line. The measured transmission, recorded on a logarithmic scale, is normalized to its maximum and corrected by an envelope function of the transducer response. (Bottom) In solid line, squared phonon displacement corresponding to the central frequency of the gap. The dashed line represents the material acoustic impedance and serve to identify the position in the sample.