title: Acoustic dispersive prism.
abstract: The optical dispersive prism is a well-studied element, which allows separating white light into its constituent spectral colors, and stands in nature as water droplets. In analogy to this definition, the acoustic dispersive prism should be an acoustic device with capability of splitting a broadband acoustic wave into its constituent Fourier components. However, due to the acoustical nature of materials as well as the design and fabrication difficulties, there is neither any natural acoustic counterpart of the optical prism, nor any artificial design reported so far exhibiting an equivalent acoustic behaviour. Here, based on exotic properties of the acoustic transmission-line metamaterials and exploiting unique physical behaviour of acoustic leaky-wave radiation, we report the first acoustic dispersive prism, effective within the audible frequency range 800 Hz-1300 Hz. The dispersive nature, and consequently the frequency-dependent refractive index of the metamaterial are exploited to split the sound waves towards different and frequency-dependent directions. Meanwhile, the leaky-wave nature of the structure facilitates the sound wave radiation into the ambient medium.
authors.affiliation: Ecole Polytechnique Fédérale de Lausanne, Laboratoire de Traitement des Signaux LTS2, Lausanne, Switzerland.|Ecole Polytechnique Fédérale de Lausanne, Laboratoire d'Electromagnétisme et d'Antennes LEMA, Lausanne, Switzerland.
authors.forename: Hussein
authors.initials: H
authors.lastname: Esfahlani
authors.affiliation: Ecole Polytechnique Fédérale de Lausanne, Laboratoire de Traitement des Signaux LTS2, Lausanne, Switzerland.
authors.forename: Sami
authors.initials: S
authors.lastname: Karkar
authors.affiliation: Ecole Polytechnique Fédérale de Lausanne, Laboratoire de Traitement des Signaux LTS2, Lausanne, Switzerland.
authors.forename: Herve
authors.initials: H
authors.lastname: Lissek
authors.affiliation: Ecole Polytechnique Fédérale de Lausanne, Laboratoire d'Electromagnétisme et d'Antennes LEMA, Lausanne, Switzerland.
authors.forename: Juan R
authors.initials: JR
authors.lastname: Mosig