Generation of topologically diverse acoustic vortex beams using a compact metamaterial aperture
- U.S. Naval Research Laboratory, Code 7165, Washington, D.C. 20375 (United States)
- National Research Council Research Associateship Program, U.S. Naval Research Laboratory, Washington, D.C. 20375 (United States)
- U.S. Naval Research Laboratory, Code 7160, Washington, D.C. 20375 (United States)
Here, we present a class of metamaterial-based acoustic vortex generators which are both geometrically simple and broadly tunable. The aperture overcomes the significant limitations of both active phasing systems and existing passive coded apertures. The metamaterial approach generates topologically diverse acoustic vortex waves motivated by recent advances in leaky wave antennas by wrapping the antenna back upon itself to produce an acoustic vortex wave antenna. We demonstrate both experimentally and analytically that this single analog structure is capable of creating multiple orthogonal orbital angular momentum modes using only a single transducer. The metamaterial design makes the aperture compact, with a diameter nearly equal to the excitation wavelength and can thus be easily integrated into high-density systems. Applications range from acoustic communications for high bit-rate multiplexing to biomedical devices such as microfluidic mixers.
- OSTI ID:
- 22590742
- Journal Information:
- Applied Physics Letters, Vol. 108, Issue 22; Other Information: (c) 2016 U.S. Government; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
- Country of Publication:
- United States
- Language:
- English
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