计算全息检测离轴非球面的离散相位计算

为了设计检测离轴非球面的计算全息图（CGH），需要对采样点的相位进行计算。通过平移和旋转，将离轴非球面几何中心的法线作为检测光路光轴。在此基础上，采用光线追迹法，对离轴非球面上采样点的相位分布进行了研究，详细推导了离散相位的计算方法，给出了在3维空间坐标系中，离轴非球面上任意一采样点的相位计算公式，并通过计算、对比同一旋转对称非球面的相位分布对该算法进行了验证。结果表明该计算方法正确，且计算精度能够满足CGH的要求。

Discrete phase calculation of computer generated hologram for off-axis aspheric surface test

The phase of sample point should be calculated to design the computer generated hologram(CGH) for testing off-axis aspheric surface. The normal of the geometric center of off-axis aspheric surface was seen as the detection optical axis through shift and rotation. Then the phase distribution on off-axis aspheric surface was studied by ray tracing, and a calculation method of discrete phase was deduced, as well as the formulas for phase computation in three-dimensional coordinate system. The validity of this method is proven by calculating and comparing the phase distribution of a rotational symmetry aspheric surface. The results show that this method is correct, and the calculation accuracy can meet the requirement of CGH for off-axis aspheric surface test.