The performance of wavefront corrector (WFC) plays a decisive role in the overall effectiveness of an adaptive optical (AO) system. When compared with commonly used WFCs, magnetic fluid deformable mirrors (MFDMs) have advantages of large stroke, low cost, and smooth continuous surface. However, the application of MFDMs is limited by the measuring range of the wavefront sensor (WFS) in the traditional AO systems. In addition, WFS needs one more optical path to measure the wavefront, which makes the AO system structure complex. In this article, a wavefront sensorless AO system based on MFDM is proposed to eliminate the limitations imposed by WFS. The stochastic parallel gradient descent (SPGD) algorithm is introduced in the control system to deform the surface of MFDM without the need to measure the wavefront. The MFDM with the proposed SPGD algorithm is applied to an optical tweezer system to eliminate the aberration caused by the optical system error and refractive index mismatch. Experimental results show that the divergent beam can be adaptively focused to successfully capture micro-particles.

中文翻译：

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利用磁流体变形镜进行波前无传感器像差校正，用于光镊系统中的激光聚焦控制


波前校正器（WFC）的性能对于自适应光学（AO）系统的整体效果起着决定性作用。与常用的WFC相比，磁流体变形镜（MFDM）具有行程大、成本低、连续表面光滑等优点。然而，MFDM 的应用受到传统 AO 系统中波前传感器 (WFS) 的测量范围的限制。此外，WFS需要多一条光路来测量波前，这使得AO系统结构变得复杂。在本文中，提出了一种基于 MFDM 的波前无传感器 AO 系统，以消除 WFS 带来的限制。控制系统中引入随机并行梯度下降（SPGD）算法，无需测量波前即可使MFDM表面变形。将所提出的 SPGD 算法的 MFDM 应用于光镊系统，以消除光学系统误差和折射率失配引起的像差。实验结果表明，发散光束可以自适应聚焦，成功捕获微粒。