Sub-aperture stitching-based high-accuracy planar optical element face type detection method

The invention relates to a sub-aperture stitching-based high-accuracy planar optical element face type detection method. A detection device comprises a two-dimensional translation table, an interferometer and a standard planar lens. The method specifically comprises the following steps: fixing a planar optical element on the two-dimensional translation table and arranging the interferometer aiming at the position of the planar optical element; adjusting the two-dimensional translation table to reach a specified target distribution region to align an exit pupil of the interferometer with a geometric central part of the planar optical element; sampling, measuring and calculating the geometric central part by the interferometer to obtain sub-aperture face type information; and repeating the steps until the measurement of all sub-apertures is finished, thereby realizing sub-aperture measurement of the planar optical element. According to the method, the complete face type of the measured planar element is restored through a certain stitching algorithm aiming at the characteristic of higher planarity of the face type of the high-accuracy planar optical element, and an economic and effective detection method is provided for checking the face type of the high-accuracy planar optical element.