Theoretical proposal for the experimental realisation of a monochromatic electromagnetic knot

Cameron, R P and Löeffler, W and Stephan, K D (2021) Theoretical proposal for the experimental realisation of a monochromatic electromagnetic knot. Journal of Optics (United Kingdom), 23 (6). 064006. ISSN 0972-8821 (https://doi.org/10.1088/2040-8986/abfc33)

[thumbnail of Cameron-etal-JO-2021-Theoretical-proposal-for-the-experimental-realisation]
Preview
Text. Filename: Cameron_etal_JO_2021_Theoretical_proposal_for_the_experimental_realisation.pdf
Final Published Version
License: Creative Commons Attribution 4.0 logo

Download (1MB)| Preview

Abstract

We propose an antenna designed to generate monochromatic electromagnetic knots and other 'unusual electromagnetic disturbances' in the microwave domain. Our antenna is a spherical array of radiating dipolar elements configured to approximate the desired electromagnetic field near its centre. We show numerically that a specific embodiment of the antenna with a radius of 61.2 cm and only 20 element pairs driven at a frequency of 2.45 GHz can yield linked and torus-knotted electric and magnetic field lines approximating those of an 'electromagnetic tangle': a monochromatic electromagnetic knot closely related to the well-known Raada-Hopf type electromagnetic knots but simpler in its construction. The antenna could be used to locally excite plasmas.