Complex optical vortex knots

Abstract: The curves of zero intensity of a complex optical field can form knots and links: optical vortex knots. Both theoretical constructions and experiments have so far been restricted to the very small families of torus knots or lemniscate knots. Here we describe a mathematical construction that presumably allows us to generate optical vortices in the shape of any given knot or link. We support this claim by producing for every knot $K$ in the knot table up to 8 crossings a complex field $\Psi:\mathbb{R}^3\to\mathbb{C}$ that satisfies the paraxial wave equation and whose zeros have a connected component in the shape of $K$. These fields thus describe optical beams in the paraxial regime with knotted optical vortices that go far beyond previously known examples.