| 摘要 |
PROBLEM TO BE SOLVED: To provide a diffractive optical element which can have high diffraction efficiency for diffracted light of specific order (design order) in a wide wavelength range and sufficiently suppress unnecessary diffracted light, and is easy to manufacture. SOLUTION: The diffractive optical element 10 is so constituted that diffraction gratings 18 and 19 made of first and second materials have grating surfaces 18a and 19a brought into contact with each other. The second material is obtained by mixing a particle material meeting conditions (10) and (11) with a resin material and the first and second materials satisfy all of conditions (1) to (9). COPYRIGHT: (C)2009,JPO&INPIT
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