Multi-aperture near-field large-area optical system and design method of scanning lens

The invention discloses a multi-aperture near-field large-area optical system and a design method of a scanning lens. The system comprises a rear optical part, aperture of an optical channel A, aperture of an optical channel B, a two-dimensional diffracting turning lens and a two-dimensional scanning lens. The two-dimensional scanning lens two-dimensionally scans a target in an area ABCDEF of a detected face. According to the principle of reversibility of an optical path, the design method of the scanning lens includes the steps of establishing a coordinate system, and calculating coordinates of faces and points; establishing a model in an optical design file, and solving the model; 1, solving coordinate attitude of the two-dimensional turning lens, 2, setting visual-field vignetting factors of two apertures, 3, solving coordinate attitude of the two-dimensional scanning lens, 4, modeling visual fields of the apertures and scanning attitudes, 5, adjusting the attitude of the two-dimensional scanning lens in the model so that the model is made consistent to a mechanical model, and 6, determining the size of the two-dimensional scanning lens. Compared with the pure geometric light theory, the design method has the advantages calculation is more accurate and quicker.