| 摘要 |
PROBLEM TO BE SOLVED: To provide a multi-ply diffraction optical element which has improved angular characteristic. SOLUTION: In the diffraction optical element, a first diffraction element part 6 and a second diffraction element part 7 consisting of different material to each other are bonded tightly to each other and a diffraction grating groove 1 having a prescribed shape is formed on the combined surface between both of the diffraction element parts 6, 7. A light shielding film 5a is formed on a wall 3 of the diffraction grating groove 1, incident light is shielded and the occurrence of flare is suppressed. COPYRIGHT: (C)2004,JPO
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