Optical Vortex Nucleation Behind A Circular Obstruction

From whirlpools in water to tornadoes in air, vortices are a common natural phenomenon. Vortices also occur in light, opening up the possibility of using light to study fields such as quantum computing and quantum fluids. Previously, light beams with vortices have also been used to study the spot of Arago. The spot of Arago is a landmark experiment verifying the wave nature of light by showing that a bright spot appears in the center of a beam after the beam encounters a circular obstacle. In this thesis, rather than using optical vortices to investigate the Arago spot, I instead explore using a circular Arago-like obstruction to generate optical vortices. I compare computational and experimental data where I displace a circular obstruction in the path of a Gaussian light beam, and I characterize the formation of an optical vortex pair in the far-field past the obstruction. In both sets of data, the results show that the formation of the vortex pair is dependent upon the distance of displacement of the obstruction. These results have the potential to be used to study quantum turbulence and the formation of vortices in quantum fluids containing obstacles.