光学学报, 2008, 28 (12): 2245, 网络出版: 2008-12-17
用于人眼视网膜成像照明的激光消散斑技术研究
Laser Speckle Reduction in Retina Imaging Illumination
自适应光学 视网膜成像 激光散斑 液晶空间光调制器 adaptive optics retina imaging laser speckle liquid crystal spatial modulator
摘要
以近红外激光(808 nm)作为人眼波前像差探测的信号光和视网膜成像的照明光, 液晶空间光调制器(LCOS)作为波前校正器, 用哈特曼波前探测器探测人眼像差, 构建了人眼像差自适应校正的视网膜成像系统。利用模拟眼分析了激光散斑对相机成像的影响和对哈特曼波前探测器进行像差探测的影响, 同时验证了利用旋转散射体的方法消除激光散斑的可行性和有效性; 用活体人眼进行了激光消散斑前后照明视网膜进行成像的对比实验, 并进一步利用自适应光学技术实现了对人眼像差的动态校正和视网膜细胞的连续成像。校正后, 系统波前像差的均方根值小于0 1 λ。实验表明激光消散斑后可以同时作为人眼像差探测的信号光和视网膜成像的照明光, 从而可以进行连续自适应校正和成像。
Abstract
An adaptive optical system with a liquid crystal spatial modulator device as the wave-front aberration corrector for the human retina imaging was constructed A Shack-Hartmann wave-front sensor was used to test the wave-front aberration of the eye A near-infrared (NIR) laser (808 nm) was used as the beacon light source for measuring the wave-front and the light source for the retina imaging A model eye was constructed to analyse the impact of the laser speckle on retina imaging on camera and wave-front measurement The method of rotating diffuser was confirmed feasible and valid for reducing the speckle And then, the contrast experiment that illuminates the vivo human eye by the laser with the diffuser rotating or not was carried out and the retina images with and without speckle were taken Finally a series of images of the retina cells were obtained after the aberration of the eye was corrected After correction the residual errors of the system aberration were less than 0 1 λ It is testified that the laser speckle can be reduced by rotating diffuser, and the NIR laser after speckle reduction can be used as the beacon light source and the illuminating light for the retina imaging As a result, the human eye aberration can be corrected continuously and a video of the retina can be taken.
李抄, 姜宝光, 夏明亮, 程少园, 宣丽. 用于人眼视网膜成像照明的激光消散斑技术研究[J]. 光学学报, 2008, 28(12): 2245. Li Chao, Jiang Baoguang, Xia Mingliang, Cheng Shaoyuan, Xuan Li. Laser Speckle Reduction in Retina Imaging Illumination[J]. Acta Optica Sinica, 2008, 28(12): 2245.