离轴反射式人眼视网膜成像自适应光学系统设计  

Design of reflective off-axis adaptive optical system for human retinal imaging

作　　者：程少园[1,2] 曹召良[1] 胡立发[1] 穆全全[1] 李鹏飞[1,2] 宣丽[1] 

机构地区：[1]中国科学院长春光学精密机械与物理研究所应用光学国家重点实验室,吉林长春130033 [2]中国科学院研究生院,北京100039

出　　处：《光学精密工程》2010年第3期609-615,共7页Optics and Precision Engineering

基　　金：国家自然科学基金资助项目(No.50703039);国家自然科学重点基金资助项目(No.60736042;No.60578035)

摘　　要：为了实现活体人眼视网膜的高分辨率成像,设计了一套视网膜成像液晶自适应光学系统来校正人眼的动态变化像差。基于开环双波段模式,分别采用夏克-哈特曼波前传感器(SHWS)和基于硅基板上的液晶空间光调制器(LCOS-SLM)来探测和校正人眼以及系统的波前像差;且分别采用近红外波段(790nm)的超发光二极管和可见光波段(570nm)的激光器作为波前探测和校正成像光源。系统采用离轴反射式结构来提高光能利用率,减小色差。用ZEMAX对系统性能进行了分析,证明设计的系统能够达到衍射极限,MTF@30lp/mm为0.4(对应视网膜上4μm),MTF@50lp/mm为0.16(对应视网膜上2.5μm)。和闭环折射式系统相比,能量利用率提高1倍以上,且杂光和色差干扰小,成像对比度好。In order to obtain the high resolution human retinal images in vivo, an adaptive optical （AO） system for retinal imaging was designed to correct the dynamic human eye wavefront aberrations, especially high order ones. On the basis of an open-loop and two-wavelength mode, the system adopted a Shark-Hartmann wavefront sensor （SHWS） and a liquid crystal spatial light modulator to detect and correct the wavefront aberrations respectively and used a 790 nm near infrared luminescent diode and a 570 nm visible laser for the wavefront detection and retinal imaging. Furthermove,a reflective off-axis system was adopted to enhance the energy-utilizing rate and to avoid the chromatic aberrations and stray light. The optical system was simulated and analyzed with ZEMAX and results show that the optical system can achieve the diffractive limit, and MTF@30 lp/mm is 0.4（4 μm atretina） ,MTF@50 lp/mm is 0.16（2.5 μm at retina）. Compared with the close-loop refractive AO system,the system has doubled the energy-utilizing rate at least,and shows its some merits in high energy-utilizing rate, low stray light and little disturbing effect caused by chromatic aberrations.

关 键 词：自适应光学 视网膜成像 液晶空间调制器 开环 

分 类 号：TH703[机械工程—仪器科学与技术] TH786[机械工程—精密仪器及机械]