开环双波段人眼视网膜成像液晶自适应光学系统设计

Design of LC Adaptive Optics System for Human Retinal Imaging Operated on Open-Loop and Two-Wavelength Mode

设计了一套基于开环双波段模式的人眼视网膜成像液晶自适应光学系统。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。探测波段采用830nm近红外光,成像波段采用790nm近红外光。采用开环模式以提高光能利用率和系统的稳定性,采用双波段模式以增大视场。新加入了瞳孔监控子系统和响应矩阵测量子系统,使系统更加灵活方便。介绍了系统的关键参数,并通过ZEMAX软件对光学系统进行模拟分析,认为系统可以达到接近衍射极限的效果。传递函数MTF@50lp/mm达到0.25(对应视网膜上3μm),满足设计要求。

An adaptive optics （AO） retinal imaging system based on liquid crystal spatial light modulator was presented, which was operated on 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 wavefront aberrations respectively. 830 nm near infrared light was used for the wavefront detection, and 790 nm near infrared light was used for retinal imaging. The open-loop mode can enhance the light efficiency and improve the system stabilization; the two-wavelength mode can enlarge the view field. The subsystems of pupil monitoring and respond matrix measuring were introduced to make the system more convenient. Some key parameters were introduced, and the optical system was simulated and analyzed with ZEMAX. It shows that the optical system can reach the diffraction limitation, and MTF@50 lp/mm of 0.25 （3 μm at retina）, which satisfies the design requirements.