Using speckle to generate optical vortices

The dark spots in the speckle pattern are the phase singularities, which contain rich information regarding the phase of the speckle field and determine the distribution of the speckle field. The generation of optical vortices using speckle is a simple, effective, and easy to implement method. we designed an experimental scheme that can generate a optical vortex to explain the properties of phase singularities in a speckle field. Through numerical simulation, we obtained the distribution of the real part zero line and the imaginary part zero line in the speckle field, and drew the singular skeleton of the speckle field, indicating that there are phase singularities in the speckle field.The experimental results are in agreement with those obtained from numerical simulations, thus verifying that the generation of optical vortices can be produced using the scattering method. The experimental scheme is simple and easy to operate.