Generation of partially coherent light with twist phase and circular-cosine coherence.

Partially coherent optical beams with twist phase have garnered significant attention due to their ability in optical engineering and imaging. However, a notable limitation in experimental synthesis has been the limited variety of light sources realized for generating these beams, which have largely been confined to uniform coherence structures. This paper examines a method for generating a novel twisted stochastic light source that exhibits not only a twist phase but also a circular-cosine coherence structure, maximizing the coherence among equidistant points from the center, varying in a cosine pattern with angular separation. We call this non-uniformly correlated light source a partially coherent light with twist phase and circular-cosine coherence. This work demonstrates its generation and experimentally characterizes its coherence features. This unique beam design enables flexible control over both radial and azimuthal coherence dimensions, coupled with the twist phase, thereby rendering it highly adaptable for diverse optical applications.