Deep sub-wavelength vortices by nonlinear mixing

Abstract

By using the nonlinear self-demodulation of two confocal vortices, we report the generation of acoustic vortices of deep sub-wavelength dimensions. A helicoidal acoustic source with two different slopes is used to generate two primary focused vortices beams with finite amplitude of different frequencies and topological charges. The self-demodulated vortex presents the spatial distribution of the main vortices with a sub-wavelength size when compared to its wavelength. Nonlinearity enables the generation of focused vortex beams of tunable topological charge in the far-field whose characteristic size is 22 times smaller than its wavelength.

@inproceedings{JimenezMetamaterials2021Vortex,
 author = {Vicente Romero-García and Aroune Duclos and Ruben Dario Muelas-Hurtado and Joao Ealo and Noé Jiménez},
 booktitle = {METAMATERIALS 2021. 15th International Congress on Artificial Materials for Novel Wave Phenomena. New York, 20 - 25 September},
 editor = {Metamorphose},
 isbn = {ISSN: 0001-4966},
 month = {09},
 organization = {The City University of New York},
 publisher = {AIP Publishing},
 series = {Oral},
 title = {Deep sub-wavelength vortices by nonlinear mixing},
 year = {2021}
}