Two types of bound in continuum states in a solid layer embedded in a liquid

• Main Authors: Amrani, Madiha, Quotane, Ilyas, Ghouila-Houri, Cecile, El Boudouti, El houssaine, Rouhani, Bahram Djafari, Krutyanskiy, Leonid, Piwakowski, Bogdan, Talbi, Abdelkrim
• Format: Conference Proceeding
• Language: English
• ISSN: 1939-800X
• DOI: 10.1121/2.0001202

In this communication, we show both theoretically and experimentally the possibility of existence of bound in continuum (BIC) states in a single solid layer embedded in a liquid. Two types of BIC states can be found: symmetry-protected SP-BIC and Fabry-Perot FP-BIC states. SP-BIC states occur as the consequence of the decoupling between longitudinal and transverse waves in the solid layer at normal incidence giving rise to bound modes of transverse polarization in the solid layer that do not interact with continuum modes of the two liquids surrounding the solid layer. FP-BIC states exist as the intersection of symmetric and/or anti-symmetric Lamb modes of the free solid layer and the transmission zeros induced by the solid layer. All these modes solely originate from the solid layer and do not depend on the nature of the surrounding liquid. The theoretical existence of BIC modes is demonstrated through an analysis of the dispersion relations and densities of states. The experimental evidence of these modes is shown by means of the transmission spectra in the ultrasonic domain.