Generating a hollow twisted correlated beam using correlated perturbations

Abstract

In this study, a twisted correlated optical beam with a dark hollow center in its average intensity is synthesized by correlated correlation perturbation and incoherent mode superposition. This new hollow beam has a topological charge (TC) mode with a zero value compared with a coherence vortex that has a TC mode with a nonzero value. We transform the twisted correlated beam from solid centered to dark hollow centered by constructing a correlation between the twist factor and the spot structure parameter. Theoretical and experimental results show that twist correlation makes the random optical beam an asymmetric orbital angular momentum spectral distribution and a tunable intensity center. Controlling the correlation parameters can make the focal spot of the twisted beam a dark core when the dominant mode of the TC is still zero. The new nontrivial beams and their proposed generation method provide important technical preparations for the optical particle manipulation with low coherence environment.