非相干数字全息自适应光学波前校正特性研究

Correction Characteristics of Wavefront Aberration in Incoherent Digital Holographic Adaptive Optics

非相干数字全息自适应光学是一种新型的自适应波前探测和校正的技术。它利用全息图可以完整记录光波场的特性进行波前探测,结合适当的数值再现算法对光波前像差进行校正。基于菲涅耳非相干相关数字全息术(FINCH),从理论上阐明了非相干数字全息自适应的基本原理,并给出了数值仿真结果。采用改进的迈克耳孙干涉仪光路配置,分别记录待观测物体与引导星的全息图,利用引导星全息图的复共轭对待测物光波进行波前校正,从实验上定量地研究了引导星尺寸、选取位置对波前校正效果的影响,在系统各光学元件给定的情形下,明确了引导星选择的空间和系统等晕区范围,实现了良好的波前校正效果。

Incoherent digital holographic adaptive optics is a new technology of wavefront sensing and correction.Combined with appropriate numerical algorithm,wavefront sensing and compensation can be achieved by the wavefront recording and reconstruction ability of the holography.Based on the basic principle of the Fresnel incoherent correlation holography（FINCH）,the incoherent digital holographic adaptive optics is investigated through theoretical analysis and simulations.Holograms of the guide star and the distorted object are recorded respectively using a modified Michelson interferometer.Aberrations in the distorted hologram can be compensated digitally by using the complex conjugate of the guide star hologram.The effect of the size and position of the guide star on the wavefront compensation are investigated quantitatively through experiments. The aberrations can be well compensated by the guide star chosen from a suitable area which is measured by the parameters of system.Furthermore,the isoplanatic region of the system is demonstrated.