Double-ring perfect vortex beams (DR–PVBs) have attracted increasing attention due to their unique characteristics of carrying independent information channels and exhibiting higher security and stability during propagation. In this study, we theoretically simulated and experimentally generated DR–PVBs with various topological charges. We investigated the propagation characteristics of these beams under von Karman spectrum turbulence conditions through numerical simulations based on multiple-phase screen methods. The effects of different inner and outer ring topological charges and varying turbulence intensities on the intensity distribution, beam spreading, and beam wander of DR–PVBs over different propagation distances were examined and compared with double-ring Gaussian vortex beams (DR–GVBs). The simulation results indicate that within a propagation range of 0–500 m, the effective radius of DR–PVBs with different topological charges remains essentially unchanged and stable. For propagation distances exceeding 1000 m, DR–PVBs exhibit superior beam wander characteristics compared to DR–GVBs. Additionally, two occurrences of self-focusing effects were observed during propagation, each enhancing beam stability and reducing the beam spreading and beam wander of the DR–PVBs. This study provides valuable insights for applications of DR–PVBs in optical communication, optical manipulation, and optical measurement.

Fractional vortex beams have attracted increasing attention due to their complex yet intriguing physical properties, such as radial notch intensity distribution and higher degrees of modulation in orbital angular momentum. In this study, we experimentally investigated and compared the beam spread and beam wander characteristics of fractional-order vortex beams with those of integer-order vortex beams after passing through a turbulent atmosphere simulator with varying turbulence intensities. Our results revealed that the beam spread of both fractional-order and integer-order vortex beams increased in a stepwise manner with the topological charge number, indicating that a larger topological charge number resulted in more severe beam spread. Interestingly, we observed that the beam radius of fractional-order vortex beams between two adjacent integer orders initially grew slowly and then rapidly before finally stabilizing into a curvilinear growth trend. This is in contrast to the linear growth trend exhibited by the beam radius of integer-order vortex beams. Furthermore, we found that the growth of the beam radius of half-integer-order vortex beams followed the linear growth trend of the beam radius of integer-order vortex beams. When the integer part of the topological charge was fixed, we observed that stronger turbulence resulted in more severe beam wander for both integer-order and fractional-order vortex beams, with the variance of the center-of-mass drift following the same growth curve. However, when the turbulence intensity is constant, both integer-order and fractional-order vortex beams exhibit a weaker beam wander effect with increasing topological charge. Our findings may provide valuable insights for applications such as optical communication and optical measurement using fractional-order vortex beams.

Partially coherent vortex beams have attracted growing interest due to their enhanced robustness and unique propagation characteristics in complex media. In this work, we experimentally investigate the behavior of partially coherent fractional vortex beams as they propagate through atmospheric turbulence. The beams are generated using a phase-only spatial light modulator and a rotating ground-glass disk modeled by the Gaussian Schell framework, and their degree of partial coherence is quantitatively characterized using a Young’s double-slit interference plate. After transmission through a 1.2 m turbulence simulator, the effective beam radius exhibits a smoothed, quasi-linear growth trend between successive integer topological charges, indicating the suppression of discrete modal transitions by the combined effects of partial coherence and turbulence. The scintillation index decreases overall with increasing topological charge, while local enhancements near half-integer orders reveal the heightened turbulence sensitivity of modal interference. Moreover, partially obstructed PCFVBs show partial statistical self-reconstruction after turbulent propagation, whereas a fully coherent control under identical conditions shows no appreciable recovery, ruling out a purely diffractive fill-in. These results provide the first, to our knowledge, comprehensive experimental insight into the interplay among coherence, turbulence, and fractional vortex structure, offering new perspectives for designing turbulence-resistant structured-light systems.