| 摘要 |
PROBLEM TO BE SOLVED: To provide a stack type diffraction optical element with high precision that hardly has a resin peel even when used for a long period.SOLUTION: A stack type diffraction optical element has a first resin layer in a first grating shape and a second resin layer in a second grating shape stacked between a first base material and a second base material, the first resin layer having a first region and a second region at an outer peripheral part adjoining the part in the first grating shape, wherein 50≤w1/hd and 0.5≤w2/w1 hold for a mean grating height hd of the first grating shape, a radial width w1 of the first region parallel with a surface of a first glass base material, and a radial width w2 of the second region parallel with the surface of the first glass base material.SELECTED DRAWING: Figure 1 |
