采用比例-微分控制器的开环液晶自适应光学系统带宽的改善

Improved bandwidth of open loop liquid crystal adaptive optics systems with a proportional-derivative controller.

作者信息

Zhang Xingyun, Cao Zhaoliang, Yang Chengliang, Peng Zenghui, Mu Quanquan, Xuan Li

出版信息

Opt Express. 2019 Apr 15;27(8):11651-11660. doi: 10.1364/OE.27.011651.

DOI:10.1364/OE.27.011651

Abstract

Open loop liquid crystal adaptive optics (LC AO) has overcome the disadvantage of low energy efficiency after years of research, and its use is very promising in ground-based large aperture telescopes for visible band imaging. However, the low system bandwidth of open loop LC AO still limits its application. In order to solve this problem, we bring the concept of proportional-derivative control (which is widely used in closed loop systems) into open loop LC AO in this paper. Experiment results verified that the system -3 dB rejection bandwidth could improve from 75 Hz to 112 Hz when tip-tilt aberration is introduced, and the mean relative contrast ratio of imaging results could improve 80% when high-order aberrations are introduced. The proposed control method has significant meaning in promoting the application of open loop LC AO in ground-based large aperture telescopes for visible imaging.

摘要

经过多年研究，开环液晶自适应光学（LC AO）克服了能量效率低的缺点，在用于可见波段成像的地基大口径望远镜中具有很大的应用前景。然而，开环LC AO的系统带宽较低，仍然限制了其应用。为了解决这个问题，本文将比例 - 微分控制（在闭环系统中广泛使用）的概念引入开环LC AO。实验结果表明，引入倾斜像差时，系统的 -3 dB抑制带宽可从75 Hz提高到112 Hz；引入高阶像差时，成像结果的平均相对对比度可提高80%。所提出的控制方法对于推动开环LC AO在用于可见光成像的地基大口径望远镜中的应用具有重要意义。