Vortex Formation In Light Due To A Blockage
Light demonstrates behaviors comparable to fluids. Developing the connection between fluids and optics may lead to a more accessible way to study systems such as superfluids. Like in fluids, a vortex forms in light where there is a wrapping of the phase. This project investigates vortex formation behind a blockage. In previous experiments, when an elliptical blockage was perpendicular to the radius of a laser beam, a pair of vortices formed behind the blockage. When the blockage was aligned radially, no vortices formed. We extend these results by investigating what happens at the start of the beam propagation, where past experiments failed to explore. In the experimental set-up, a beam passes through a spatial light modulator, onto which a grating pattern with an opaque elliptical blockage is projected. A camera and imaging set-up images the beam. No vortices formed at zero propagation, as expected from computational simulations. If vortices do not form immediately, it raises the question where nucleation actually occurs. Our results motivate further investigation into the formation of vortices to fill in the gaps of computational models and to explore the implications for fluids.
