遗传算法在自适应光学系统中的应用

为了校正激光光束的波前像差,建立了一套无需直接探测波前信息的自适应光学(AO)系统模型,提出了一种基于实数编码的高斯变异的遗传算法(GA)用来控制61单元压电变形镜补偿波前像差,并仿真利用此算法控制61单元变形镜校正由变形镜本身产生的像差。结果表明,这种算法能够找到补偿各种像差所需的变形镜的最优面型。像差校正后,焦平面的峰值光强最多能够提高30倍。环围斯特尔比值(Strehl ratio)最多能够从校正前的0.032提高到0.96,变形镜61个驱动器后的电压值收敛性能良好。

Study of a Genetic Algorithm Used in an Adaptive Optical System

For correcting the phase aberration in wavefront,a wavefront sensor-less adaptive optical(AO) system was set up,and a real number encoding Gauss mutation genetic algorithm which was applied to control a 61-channel deformable mirror(DM) was developed.Phase aberration generated by randomly adding voltages to the 61 channels of DM was brought to an ideal incident wavefront.Several simulation experiments have been done.The simulation results demonstrated that this algorithm could find the optimum DM shape which was applied to correct phase aberration.After the phase aberration in incident wavefront was corrected with this technique,the peak light intensity on the focal plane could at most be improved by a factor of 30,and the encircled energy Strehl ratio was increased to 0.96 from 0.032.It is also found that the convergence and stability of the 61 voltages on the DM is quite well.