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arXiv · 1510.00228

Photoacoustic ultrasound sources from diffusion-limited aggregates

Krutik Patel·Morgan Brubaker·Alexander Kotlerman·Robert Salazar·Eli Wolf·David Weld
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Abstract

Metallic diffusion-limited aggregate (DLA) films are well-known to exhibit near-perfect broadband optical absorption. We demonstrate that such films also manifest a substantial and relatively material-independent photoacoustic response, as a consequence of their random nanostructure. We theoretically and experimentally analyze photoacoustic phenomena in DLA films, and show that they can be used to create broadband air- coupled acoustic sources. These sources are inexpensive and simple to fabricate, and work into the ultrasonic regime. We illustrate the device possibilities by building and testing an optically-addressed acoustic phased array capable of producing virtually arbitrary acoustic intensity patterns in air.

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Krutik Patel, Morgan Brubaker, Alexander Kotlerman, Robert Salazar, Eli Wolf, David Weld. 2016-10-15. Photoacoustic ultrasound sources from diffusion-limited aggregates. https://doi.org/10.1063/1.4966993

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