哈特曼波前传感器中采样点数的分析

随着哈特曼传感器测量口径的增大,采样点数对被测波前的空间分辨率、测量精度及动态范围的影响也随之增大,因此通过计算机仿真波前径向斜率拟合过程,分析出采样点数和斜率探测误差对测量精度和测量范围的影响。计算机仿真的波前斜率拟合所用泽尼克多项式达到121项,测量口径2m,测量精度要求λ/50,径向(半径)和切向最少采样点数分别为10点和21点。当径向和切向采样点数分别为40点和250点,斜率测量误差为0.045″时,所测波前的P-V值范围是0-4λ。

Analysis of sampling points in Hartmann wavefront sensor

With the diameter of Hartmann wavefront sensor increases,the sampling points on the spatial resolution,measurement accuracy and dynamic range of the measured wave front impact also increase.Through the fitting process of computer simulation on the wavefront radial slope,the impact of the sampling points and the measurement error of the slope on the measurement accuracy and measurement range are analyzed.By computer simulation,Zernike polynomials used on fitting wave-front slope reach 121 items,measuring diameter is 2m,accuracy is λ/50,radial(radius) and tangential sampling points are at least 10 points and 21 points.When the radial and tangential sampling points are 40 points and 250 points,the slope measurement error is 0.045",the measured wavefront PV value range is 0-4λ.