The use of random phase patterns composed of huge number of elements for wavefront reconstruction in adaptive optics

The wavefront reconstruction with interaction matrix composed of high-order Zernike polynomials as basis may be unintendedly less accurate when the wavefront manipulator of huge number of elements such as Microelectromechanical systems (MEMS) mirrors and Liquid Crystal on Silicon (LCOS) is used. One of the reasons of the lack of the accuracy in reconstruction comes from the mismatch between the rectangular elements of the LCOS in the orthogonal arrangement and the projected patterns obtained by the Zernike polynomials defined in the polar coordinates. To improve the accuracy of the wavefront reconstruction by the LCOS, the use of the random phase patterns is proposed with presumption to be appropriate for the orthogonally arranged high number of elements. The residual fitting errors of reconstructed wavefront are evaluated by numerical simulation to show the potential of the use of the random phase patterns instead of the use of the Zernike polynomials. It is found by the Monte-Carlo simulation of the Kolmogorov model that the more random phase patterns one uses, the more accurate one achieves to reconstruct the wavefront compared to the use of the Zernike patterns. Additionally, the comparison of the Strehl ratio of the AO system obtained with the Zernike patterns and that of the random patterns is performed.