基于模型的无波前传感器磁流变液变形镜大像差校正

Large Aberration Correction by Magnetic Fluid Deformable Mirror with Model-Based Wavefront Sensorless Control Algorithm.

机构信息

Department of Precision Mechanical Engineering, Shanghai University, Shanghai 200444, China.

Dunlap Institute for Astronomy and Astrophysics, University of Toronto, Toronto, ON M5S 3H4, Canada.

出版信息

Int J Mol Sci. 2019 Jul 28;20(15):3697. doi: 10.3390/ijms20153697.

DOI:10.3390/ijms20153697

PMID:31357727

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC6695980/

Abstract

Magnetic fluid is a stable colloidal suspension of nano-sized, single-domain ferri/ferromagnetic particles dispersed in a liquid carrier. The liquid can be magnetized by the ferromagnetic particles aligned with the external magnetic field, which can be used as a wavefront corrector to correct the large aberrations up to more than 100 µm in adaptive optics (AO) systems. Since the measuring range of the wavefront sensor is normally small, the application of the magnetic fluid deformable mirror (MFDM) is limited with the WFS based AO system. In this paper, based on the MFDM model and the relationship between the second moment (SM) of the aberration gradients and the far-field intensity distribution, a model-based wavefront sensorless (WFSless) control algorithm is proposed for the MFDM. The correction performance of MFDM using the model-based control algorithm is evaluated in a WFSless AO system setup with a prototype MFDM, where a laser beam with unknown aberrations is supposed to produce a focused spot on the CCD. Experimental results show that the MFDM can be used to effectively compensate for unknown aberrations in the imaging system with the proposed model-based control algorithm.

摘要

磁流体是一种稳定的胶体悬浮液，由纳米级、单畴铁/铁磁粒子分散在液体载体中组成。液体可以通过铁磁粒子在外磁场中的排列而被磁化，这可以用作波前校正器，以校正自适应光学（AO）系统中超过 100 µm 的大像差。由于波前传感器的测量范围通常较小，因此基于波前传感器的 AO 系统限制了磁流体可变形反射镜（MFDM）的应用。在本文中，基于 MFDM 模型和像差梯度的二阶矩（SM）与远场强度分布之间的关系，提出了一种用于 MFDM 的基于模型的无波前传感器（WFSless）控制算法。使用基于模型的控制算法对原型 MFDM 的无波前传感器 AO 系统设置中的 MFDM 的校正性能进行了评估，其中假定具有未知像差的激光束在 CCD 上产生聚焦光斑。实验结果表明，使用所提出的基于模型的控制算法，MFDM 可用于有效补偿成像系统中的未知像差。