【作者】 夏明亮；

【导师】 宣丽；

【作者基本信息】 中国科学院研究生院（长春光学精密机械与物理研究所） ， 光学， 2011， 博士

【摘要】 哈特曼波前探测器具有实时性强,易操作,可以简单方便的测量波前位相分布等优点,因此在人眼像差测量、激光光束质量诊断、光学元件、光学系统检测、大气扰动光学测量、以及自适应光学等诸多领域有着广泛的应用。本论文主要研究了用于眼底液晶自适应光学成像系统中的哈特曼波前探测器。由于人眼视网膜的光反射率只有1/1000,且由多层组织构成,各层组织的反射导致哈特曼光斑周围有一层光晕;另外人眼角膜各个部位的偏振特性不同,而本实验系统采用液晶空间光调制器作为波前校正器,必须利用偏振片滤光后进行像差校正,偏振化后就出现了光强分布不均匀的问题,因此导致位于后光路上的哈特曼光斑光强分布不均匀。本论文提出了多峰逐点阈值算法解决了此问题。研究了光强加幂算法,并将它与多峰逐点阈值算法融合在一起使哈特曼波前探测器的探测精度提高到1%像素,对应波前PV值小于λ/40(λ=500nm)。提出了一种动态追踪质心探测算法,仅通过软件手段在不降低探测能量,增加探测速度的基础上扩大了哈特曼波前探测器的动态范围,解决了高度屈光不正人眼的波前探测问题,此方法也适用于大气湍流测量。论文还分析了微透镜排列方式对哈特曼波前探测器质心探测精度的影响,分析了由于人眼瞳孔变化引起的重构误差,提出了动态重构方法。利用Zernike模式的对称性,优化了GPU波前重构算法,提高了波前重构速度。将所研制的哈特曼波前探测器用于人眼眼底自适应光学成像系统中,获得了达到衍射极限水平的3微米直径的视网膜细胞轮廓图像。本论文通过软件手段在提高人眼像差探测的哈特曼波前探测精度的同时,扩大了探测动态范围,不增加任何成本,因此具有良好的应用前景。更多还原

【Abstract】 Harmann wavefront has many advantages such as good real-time performance, easy operation, measuring wavefront slope easily and visual display wavefront distortion, so it is widely applied in many fields such as the laser beam quality diagnosis, optical components and optical system detection, atmospheric disturbances measurement, eye aberration measurement and adaptive optics etc.A hartmann wavefront detector for liquid crystal adaptive optics fundus imaging system is tried to deveop in the paper. Due to the reflection of each layer of the human eye tissue, causing the halo around the spot image; The different polarization characteristics as different place of the cornea, and using liquid crystal spatial light modulator as wavefront correctors in our laboratory, polarization light should be used to correct aberration, therefore light intensity distribution of Hartmann spot image is uneven when polarized. A new thresh algorithm of multimodal and point by point selection thresh is developed to solve above proplem in the paper. The light intensity with power algorithm is studied, and it is merged with the multimodal and point by point thresh selection thresh algorithm together to improve the precision of Hartmann wavefront detector to 1% pixels, and the corresponding PV value of the wavefont is less thanλ/40(λ=500nm). A dynamic tracking centroid detection algorithm is developed to solve the problem of the large eye aberration detection, which expand the dynamic range of Hartmann wavefront detector only by software means without loss of accuracy and increasing the detection time and is also applicable to the atmospheric turbulence measurement. The influence of the microlens arrangement for the centroid detection precision of Hartmann wavefront detector is analyzed, and the reconstruction error the variation of the eye pupil size leads to is analyzed, and the dynamic wavefront reconstruction algorithm is developed to solve above problem. According to the symmetry of the Zernike mode, optimizing the GPU program and decreasing the time of the wavefront reconstruction. The development Hartmann wavefront detector is used in the experiment of adaptive optics retina imaging, and the three microns retinal image of the diffraction limit is obtained.The precision is improved and the dynamic range is expanded of Hartman wavefront detector by software means, and without additional costs, so it has a good application prospect.更多还原