| 摘要 |
A method of measuring a deviation of an optical surface from a target shape and a method of manufacturing an optical element. The method of measuring the deviation includes:—performing a first interferometric measurement using a first diffractive measurement structure, which is arranged to cover a first area of the optical surface, to provide a first interferometric measurement result,—performing a second interferometric measurement using a second diffractive measurement structure, which is arranged to cover a second area of the optical surface different from the first area, to provide a second interferometric measurement result, and—determining a deviation of the optical surface from the target shape. |
