Skulls in the Stars

Working on the second edition of my Singular Optics textbook and thought I would blog about some of the fun developments in the field that I’ve come across while doing the book research!

Light has wave properties, and as a wave it can do wavy things like other types of waves — including swirling around a central point like a vortex. When a beam of light manifests one or more of these swirling regions, it is typically referred to as a “vortex beam” and the individual swirling structures are known as “optical vortices” (naturally). Beams possessing optical vortices turn out to be really useful in a lot of applications, and the field of study of such beams, and related “singular” beams, has become known as “singular optics.”

A vortex is a localized, conserved, and discrete structure in a wavefield and when we think of vortex beams, we usually think of beams possessing a finite number of vortices. An infinite number of anything is a concept alien to physics in general, as “infinity” is generally considered an unattainable idealized limit.

I’ve been obsessed with infinity in the context of optical vortices, however, and have published some really neat results on this subject (I will elaborate momentarily). Thus when I came across a 2021 paper by Kovalev and Kotlyar¹ titled “Optical vortex beams with the infinite topological charge,” I was immediately intrigued! In this blog post I will give an overview of what optical vortices are, how they behave, and why it is fascinating that one can apparently cram an infinite number of vortices in a beam of light!