| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a laminated diffractive optical element having reduced transmittance irregularity by reducing shading formed on an image surface resulting from the difference in transmittance of the optical element. <P>SOLUTION: The laminated diffractive optical element includes: a colorant-containing first layer having a diffraction grating surface with a grating height X; and a second layer closely stacked on the diffraction grating surface of the first layer. In the optical element, the relation of internal transmittances T<SB POS="POST">λ,a</SB>and T<SB POS="POST">λ,b</SB>of a material (a) for forming the first layer and a material b for forming the second layer satisfies the following (Formula 1) and the relation of the maximum and minimum internal transmittances T<SB POS="POST">λ,MAX</SB>and T<SB POS="POST">λ,MIN</SB>of the laminated diffractive optical element satisfies the following Formula (2). (Formula 1): 2.0%≤¾T<SB POS="POST">λ,a</SB>-T<SB POS="POST">λ,b</SB>¾ and (Formula 2): T<SB POS="POST">λ,MAX</SB>-T<SB POS="POST">λ,MIN</SB>≤8.0%. <P>COPYRIGHT: (C)2012,JPO&INPIT |
