Optical knots in engineered turbid media

In this talk we theoretically and experimentally investigate an interesting family of null solutions to Helmholtz equation in 3D free space - optical vortices, or zero lines of complex amplitude in a propagating light field, that are knotted or linked in a certain way. We design all-dielectric optical metasurfaces – nanostructures enabling unprecedented control over the amplitude, polarization and phase of optical fields, for generation of optical knots, and study their stability and evolution in engineered colloidal suspensions with saturable Kerr-like nonlinearity. These studies are further generalized to characterization of knot evolution in turbid linear and nonlinear media, such as clouds, fog, biological media, and undersea environments. Knotted electromagnetic fields may find applications in three-dimensional optical manipulations or could be considered as candidates for new information carriers in classical and quantum communication systems.