小型化人眼像差校正仪光学系统设计

为了实现活体人眼视网膜的高分辨率成像,需要实时校正人眼的动态变化像差,尤其是高 阶像差.设计了一套基于液晶空间光调制器的小型化人眼像差实时校正光学系统.该光学系统分别采用夏克-哈特曼波前传感器和液晶空间光调制器来探测和校正波前畸变.探测光采用790nm近红外光,成像光采用570nm可见光.系统设计尽量少采用透镜,减小了系统的体积、光能损失和系统自身可能引入的像差.使用开环模式可以提高光能利用率和系统的稳定性,而双波长模式可以增大视场,实现不同波长的成像,而且可以实现瞬间强曝光成像.用ZEMAX软件对光学系统进行模拟分析,表明该系统可以达到衍射极限的水平,MTF=0.5@31 cycles/mm(对应视网膜上4μm),MTF=0.3@48 cycles/mm(对应视网膜上2.6μm).实验结果证明:该系统光能利用率高,杂光干扰小,方便灵活.

Optical design of miniaturization aberration correcting system for human eye

In order to obtain the high resolution human retinal images in vivo,it was required to correct the dynamic human eye wavefront aberrations in real time,especially for high order aberrations.An optical system for human eye aberration correction was designed,which adopted Shark-Hartmann wavefront sensor(SHWS)and liquid crystal spatial light modulator(LC-SLM)to detect and correct the wavefront aberrations respectively.The 790 nm near infrared light was used for the wavefront detection,and the 570 mn visible light was used for retinal imaging.The system used less lenses,which could reduce the volume,decrease light loss and diminish the aberration of the optical system.The open-loop mode could enhance the light efficiency and improve the system stabilization;the two-wavelength mode could enlarge the view field,but also realize strong exposure imaging instantaneous.The optical system was simulated and analyzed with ZEMAX.It is showed that the optical system can achieve the diffractive limited,and MTF=0.5@31 cycles/mm(4μm at retina),MTF=0.3@48 cycles/mm(2.6 μm at retina).It is a good aberration correcting system for human eye,with some merits including high energy-utilizing rate,little disturbing effect arose by stray light,and high flexibility.