| 主权项 |
1. A method for manufacturing a diffractive optical element, comprising steps of:
preparing a die having an inverted shape relative to a shape of a diffractive surface of the diffractive optical element; and forming, by pressing a glass material with the die, the diffractive optical element having the diffractive surface, wherein raised and recessed portions are alternately arranged on the diffractive surface, a shape of valley bottoms of the recessed portions in a central region of the diffractive surface is different from that in an outer region located outside the central region, and each valley bottom of the recessed portions is formed to have a chamfered shape. |
