Analysis of correction capability of 97-element deformable mirror based on SPGD

摘要

Deformable mirror (DM) is a key component to the adaptive optics (AO) system. Its ability to fit the wavefront aberration determines the performance of the AO system. A wavefront sensorless adaptive optics (WFSless AO) system was used to investigate the fitting capability of a 97-element DM. We examined the fitting from the single order aberration of Zernike polynomial, combined aberration of Zernike polynomial and closed-loop correction, where the stochastic parallel gradient decent (SPGD) was used as close-loop correction algorithm. The results show that the 97-element DM has a good fitting ability to the first 3-54~(th) single order of Zernike aberration. When the original wavefront RMS value was one wavelength, the residual wavefront aberration RMS was less than 0.4X. The fitting to combine aberration of Zernike polynomial and closed-loop correction results based on the SPGD control algorithm show that the aberration was basically completely corrected when the wavefront aberration was small. When the wavefront aberration was relatively large, such as D/r0=20, the RMS of the residual wavefront aberration were smaller than 0.14λ (the initial RMS is 0.63X). Above analysis results can provide theoretical basis and important reference for the practical application of the 97-element DM.