Anisoplanatic effects on wave propagation through dynamic pseudo-random phase plate mimicking atmospheric turbulence

Abstract

Atmospheric turbulence significantly impacts the performance of optical systems, causing wavefront distortions that degrade image quality and limit the capabilities of remote sensing, astronomical observations, and free-space communication. The phenomenon of angular anisoplanatism, where the angular extent of the isoplanatic patch becomes limited due to varying turbulence conditions across the field of view, poses a substantial challenge in achieving high-resolution imaging of extended objects through turbulent atmospheres. This paper presents a comprehensive investigation into angular anisoplanatism using a laboratory-based environment that employs a pseudo-random phase plate to generate Kolmogorov turbulence. Angular anisoplanatism has been studied by generating two beams using a robust cyclic interferometer type arrangement, such that one beam is considered as a reference and the other beam as a target. Here, we have investigated experimentally the correlation of Zernike coefficients, mean square error (MSE), and beam centroid displacement, as a function of the angular separation of two beams. Furthermore, we have also reported the correlation of Zernike coefficients of the Laguerre Gaussian beam with different charges and eventually compared its MSE with that of the Gaussian beam.