自适应光学系统中波前传感器噪声的闭环传递特性

Closed-loop transferring characteristics of wavefront sensor noise in adaptive optical system

分析了 Shack-Hartmann波前传感器 (S-H WFS)在实际大气条件下 ,大气湍流波前相位的探测误差在自适应光学系统 (AOS)中的传递过程以及最后的控制残余方差 ,导出了定量分析的数学模型 ,并给出了分析结果。结果表明 ,当 SH-WFS用于微弱信标光大气湍流的探测时 ,自适应光学系统中的控制斜率残余误差中除了前人分析[1] 的误差外还包含一项由天空背景光斑质心位置引起的常数误差值 ,并且系统的有效控制带宽会因信标探测对比度的下降而减小 ,这将大大降低 AOS的校正能力。分析结果还表明信标光越弱 ,对 S-H

The transferring characteristics of the detecting error of adaptive optical system (AOS) under real atmospheric turbulence are presented. A mathematical model for quantitative analysis is acquired. Results show that the residual error will increase due to the beacon light's decreasing when Shack-Hartmann wavefront sensor is used in probing very low-light-level object. Because a constant term caused by sky background light is included in the control of residual error besides other terms, it is demanded that the aberration of S-H WFS calibrating optical system be very small.