Asymmetric twisted vortex Gaussian Schell-model beams

• Published in: Optics communications 2021-07, Vol.491, p.126950, Article 126950
• Main Authors: Zhang, Yao, Pan, Keming, Xu, Jia, Zhu, Weiting, Zhao, Daomu
• Format: Article
• Language: English
• Subjects: Coherence vortices; Orbital angular momentum; Rotation
• ISSN: 0030-4018; 1873-0310
• DOI: 10.1016/j.optcom.2021.126950

We analyze a family of asymmetric twisted vortex Gaussian Schell-model (ATVGSM) beams which are derived via a coupling of off-axis vortex phase and twist phase in the correlation function. Explicit expression of the orbital angular momentum (OAM) carried by such a beam is derived and the impact of the state of coherence on the OAM is demonstrated. Further, the evolution of the intensity distribution and the behaviors of the coherence vortices during propagation are explored in detail. It is shown that owing to the shift of the vortex phase dislocation such a beam has the form of a crescent which rotates upon propagation. The stability of the asymmetric dark hollow structure is deeply affected by the interaction of two kinds of phases and the change of state of coherence is induced by the twist strength. Meanwhile, the coherence vortices generate in pairs with opposite topological charge and move along certain trajectories under various conditions. Besides, the expression related to define the rotation angle is deduced and the rotating properties of the intensity pattern are discussed. •We analyze a family of ATVGSM beams.•We derived the explicit expression of OAM carried by such a beam.•The impact of the state of coherence on the OAM is demonstrated.•The intensity distributions and coherence vortices during propagation are explored.