ABSTRACT
Up to this point, we have primarily considered singularities inmonochromatic waveelds. However, even the most stable laser has randomuctuations in phase as it evolves in time, andmost natural sources of light have large uctuations in both amplitude and phase. This raises a signicant question: what happens to phase singularities when the phase is scrambled? We have seen that optical vortices are stable under perturbations of the waveeld; such perturbations presumably include passing a vortex beam through a random phase screen, turning it into a partially coherent eld.
