Elastic Bound State in the Continuum with Perfect Mode Conversion
arXiv:2103.09006 · doi:10.1016/j.jmps.2021.104502
Abstract
The partial or complete confinement of waves in an open system is omnipresent in nature and in wave-based materials and technology. Here, we theoretically analyze and experimentally observe the formation of a trapped mode with perfect mode conversion (TMPC) between flexural waves and longitudinal waves, by achieving a quasi-bound state in the continuum (BIC) in an open elastic wave system. The latter allows a quasi-BIC in a semi-infinite background plate when Fano resonance hybridizes flexural and longitudinal waves and balances their radiative decay rates. We demonstrate that when the Fabry-Pérot resonance of the longitudinal wave is realized simultaneously, the TMPC formed by the elastic BIC approaches infinite quality factor. Furthermore, we show that quasi-BIC can be tuned continuously to BIC through the critical frequency of mode conversion, which offers the possibility of TMPC with an arbitrarily high quality factor. Our reported concept and physical mechanism open new routes to achieve perfect mode conversion with tunable high quality factor in elastic systems.
arXiv comment6 figures, 25 pages
References in corpus (6)
- Resonantly Trapped Bound State in the Continuum Laser
- Topological nature of bound states in the radiation continuum
- Seismic metasurfaces: Sub-wavelength resonators and Rayleigh wave interaction
- Unusual Resonators: Plasmonics, Metamaterials, and Random Media
- Zero-index bound states in the continuum
- Transmodal Fabry-Pérot Resonance: Theory and Realization with Elastic Metamaterials
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