arXiv subjects

R. P. Cameron

Publications and source records attributed to R. P. Cameron.

3 recordsLinked to original sources

arXiv2021

Theoretical proposal for the experimental realisation of a monochromatic electromagnetic knot

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 Rañada-Hopf type electromagnetic knots but simpler in its construction. The antenna could be used to locally excite plasmas.

physics.class-ph↗

arXiv2018

Superpositions of up to six plane waves without electric-field interference

Superpositions of coherent light waves typically interfere. We present superpositions of up to six plane waves which defy this expectation by having a perfectly homogeneous mean square of the electric field. For many applications in optics these superpositions can be seen as having a homogeneous intensity. Our superpositions show interesting one- two- and three dimensional patterns in their helicity densities, including several that support bright regions of superchirality. Our superpositions might be used to write chiral patterns in certain materials and, conversely, such materials might be used as the basis of an 'optical helicity' camera capable of recording spatial variations in helicity.

physics.optics↗

arXiv2016

Stegosaurus chirality

We explain that Stegosaurus exhibited exterior chirality and observe that the largest plate in particular of USNM 4394, USNM 4714, DMNS 2818 and NHMUK R36730 appears to have tilted to the right rather than to the left in each case. Several instances in which Stegosaurus specimens have been confused with their distinct, hypothetical mirror-image forms are highlighted. We believe our findings to be consistent with the hypothesis that Stegosaurus's plates acted primarily as display structures. A collection of more than one Stegosaurus might be referred to henceforth as a 'handful' of Stegosaurus.

q-bio.PE↗