High-precision and efficient alignment of cubic phase plate based on Zernike polynomials.

Cubic phase plates are key optical elements in the wavefront coding system. Unlike for traditional optical lenses, their free-form shape makes it difficult to determine the correct position. This article presents a precise and efficient alignment method using Zernike polynomials by analytical analysis and numerical simulation and considering position deviations of rotation and offset. In addition, to help determine what kind of position deviation exists, the relationship between position deviation and introduced surface errors is analyzed and demonstrated. The proposed method is especially useful for optical design and manufacture. It improves the accuracy of measurements by eliminating error resulting from misplacement. An optical test system using a phase shift interferometer and the result of a cubic phase plate is demonstrated.