基于变形镜本征模的模型式无波前探测自适应光学系统

Model wavefront-sensorless adaptive optics system based on eigenmodes of deformable mirror

模型式无波前探测自适应光学系统以其收敛速度快、校正效果好在波前无法探测的环境中具有巨大的应用潜力。基函数的产生方法及阶数多少决定了模型式无波前探测自适应光学系统的校正效果和收敛速度,文中提出以变形镜本征模作为基函数。分别以32、88及127单元变形镜作为波前校正元件建立无波前探测自适应光学系统仿真模型,利用变形镜本征模作为正交基函数对波前畸变进行校正,分析其校正效果和收敛速度。结果表明,以变形镜本征模作为基函数时,由于基函数的阶数等于变形镜的单元数,无需另外确定阶数多少,且无波前探测自适应光学系统可以获得接近理想校正时的校正效果,系统收敛所需测量的光斑强度的次数仅取决于变形镜的单元数。

Model wavefront-sensorless adaptive optics （AO） system has a great applicaticn potential because of its fast convergence and good correction. It is important for correction effect and convergence of AO system that how to generate basis functions and determine its number of order. Eigenmodes of deformable mirror （DM）were used as basis functions in this paper. AO simulation platforms were set up with a 32- element DM, a 88-element DM and a 127-element DM respectively and the correction effect and the convergence rate were investigated. Results show that AO systems can obtain the correction capability close to the ideal correction of DM, which indicates the correction capability of DM are utilized fully. Additionally, because the number of DM eigenmodes is equal to the number of DM actuators, it is not necessary to determine the required number of modes no matter how the strength of the aberrations is. The convergence speed of AO system only depends on the number of actuators of DM.