DIFFRACTIVE LENS MANUFACTURING METHOD

摘要

Provided is a novel manufacturing method for a diffraction lens, whereby aperture and eccentricity effects can be suppressed and any multi-focusing effect can also be obtained in a more stable manner. A synchronous structure is set up where at least two reliefs (32, 34) whose first order diffracted lights give respective focal distances different from one another are set to overlap with each other in at least a part of an area in a radial direction of a diffraction lens (10), and with respect to every grating pitches of one relief (34) having the maximum grating pitch among the reliefs (32, 34) set up in overlap, grating pitches of another relief (32) are overlapped periodically; and the resulting relief pattern (30) is formed on a surface (24) of an optical material (10).