Mapping the dispersion of water wave channels

David J Apigo,Gordon A Thomas,Emil V Prodan,John Palmieri,Camelia Prodan,Alokik Kanwal,Reginald C Farrow,Kyle F Dobiszewski

doi:10.1038/s41598-018-21462-2

David J Apigo, Gordon A Thomas + Show 6 more

Open Access

https://doi.org/10.1038/s41598-018-21462-2

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Abstract

Large classes of electronic, photonic, and acoustic crystals and quasi-crystals have been predicted to support topological wave-modes. Some of these modes are stabilized by certain symmetries but others occur as pure wave phenomena, hence they can be observed in many other media that support wave propagation. Surface water-waves are mechanical in nature but very different from the elastic waves, hence they can provide a new platform for studying topological wave-modes. Motivated by this perspective, we report theoretical and experimental characterizations of water-wave crystals obtained by periodic patterning of the water surface. In particular, we demonstrate the band structure of the spectra and existence of spectral gaps.

Highlights

Wave behavior in photonic, phononic, and acoustic systems has been previously studied theoretically[1,2,3,4,5] and experimentally[4,6,7,8,9,10,11]
Resonant modes can be determined by scanning a wide frequency range and taking images or measuring the amount of light attenuated across the system utilizing laser/photodiode pairs
Utilizing the 650 nm laser diodes positioned incident to the water allowed the user to acquire quantitative data pertaining to the amplitude of the resonant modes

Summary

Introduction

Phononic, and acoustic systems has been previously studied theoretically[1,2,3,4,5] and experimentally[4,6,7,8,9,10,11]. The proposed system is significantly different from previously reported photonic and acoustic systems and presents, to our knowledge, for the first time a physical way to map the phonon spectrum of water-wave crystals in various types of channels. Unlike Chladni plates, which provide beautiful visualizations of resonant patterns and are useful in measuring modal frequencies in solids[12], this apparatus provides quantitative data pertaining to fluids. The flexibility of this system makes it extremely useful for future studies of other types of waveguides, in particular QCs. This paper reports findings on the phonon spectrum of fluids in flat-walled and periodic waveguides; this apparatus is not limited to these designs. Correspondence and requests for materials should be addressed to www.nature.com/scientificreports/

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