Holographic modal wavefront sensing for adaptive correction of turbulence-induced aberrations in vortex beam

Vortex beams carrying orbital angular momentum (OAM) offer significant potential for high-capacity free-space optical communications due to their inherent orthogonality and mode-division multiplexing capability. However, their helical phase structure is highly susceptible to distortion from atmospheric turbulence, leading to severe inter-modal crosstalk and degradation of transmission quality. Conventional wavefront sensors struggle to accurately detect phase singularities in vortex beams, limiting the effectiveness of adaptive optics systems. This paper introduces a holographic modal wavefront sensor (HMWS) for wavefront sensorless adaptive correction of turbulence-induced aberrations in vortex beams. The HMWS employs computer-generated holograms (CGH) to encode multiple Lukosz aberration modes, generating distinct focal spots whose second moment of intensity (SMI) linearly relates to the integrated square modulus of wavefront gradients (ISMWG). Theoretical analysis and numerical simulations confirm the validity of this linear relationship even under strong spiral phase distortions. Results demonstrate that the HMWS enables rapid and accurate estimation of low-order aberrations in vortex beams with arbitrary topological charges. The proposed method provides a robust, sensorless solution for real-time adaptive optics in vortex-based communication systems.