无光焦度校正板自身无色差和像面弯曲，并具有弯曲PW和光焦度■₁₁及■₁₂等变数，为光学系统的像差校正提供了很大的方便。以系统通光孔径Φ=300mm，相对孔径A=1／2，光阑位置l_p2／f=－0．75，主镜为球面反射镜为例，设计了一种带有无光焦度校正板且光阑在主反射镜前的牛顿光学系统。通过对光学系统进行光线计算、像差分析和优化，得到校正板透镜最佳光焦度■₁₁=5，优化后的轴上点波前像差W=0．0001λ。

Since a zero-power corrector itself has no achromatic aberration and Petzval curvature,and has such variables as curvature PW,powers ■₁₁ and ■₁₂,etc,it makes the correction of the aberrations of an optical system easier. A Newton optical system with a zeropower corrector,whose stop is before the primary mirror,is proposed. The parameters of the system are the clear aperture Φ 300 mm,relative aperture A= 1/2,stop position l_p2/f = －0. 75,and the eccentricity of the primary mirror e² = 0. Based on the ray calculation,aberration analysis and optimization of the optical system,the corrector lens optimal power ■₁₁= 5,and the optimized on-axis wavefront aberration W=0. 000 1λ were obtained.