DIFFRACTION OPTICAL ELEMENT, METHOD FOR MANUFACTURING THE SAME, OPTICAL SYSTEM HAVING THE DIFFRACTION OPTICAL ELEMENT, OBSERVATION DEVICE, PHOTOGRAPHING ELEMENT AND PHOTOGRAPHING DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a diffraction optical element and a method for manufacturing the same such that positioning with high accuracy can be efficiently performed and that the productivity can be improved, and to provide an optical system, an observation device, a photographing element and a photographing device having the above diffraction optical element. SOLUTION: In the diffraction optical element having layers of at least two diffraction gratings with a lens effect, a projection or recess is formed in the position except for the center of the lens effect face of one diffraction grating and is formed in the center part of the lens effective plane of the other diffraction grating.