Title:
OPTICAL ELEMENT AND OPTICAL SYSTEM AND IMAGING APPARATUS HAVING THE SAME
Document Type and Number:
Japanese Patent JP2018072624
Kind Code:
A
Abstract:
PROBLEM TO BE SOLVED: To provide an optical element in which a transmittance with desired wavelength characteristics can be obtained.SOLUTION: An optical element 10 has a substrate 11, an antireflection film 13 disposed on the substrate 11, and an absorption layer 12 disposed between the substrate 11 and the antireflection film 13 for absorbing part of incident light. The optical element 10 satisfies all of the following conditional expressions: k/λ≤2.0×10[nm] and 0.01<ΔR, where krepresents the maximum of an extinction coefficient of the absorption layer 12 in the wavelength range from 400 nm to 700 nm; λ[nm] represents a wavelength where the extinction coefficient of the absorption layer is kin the wavelength range from 400 nm to 700 nm; and ΔR represents a difference between the maximum and the minimum of the reflectance of the optical element 10 in the wavelength range from 400 nm to 700 nm.SELECTED DRAWING: Figure 1
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Inventors:
OTSUKA HIROSHI
Application Number:
JP2016213546A
Publication Date:
May 10, 2018
Filing Date:
October 31, 2016
Export Citation:
Assignee:
CANON KK
International Classes:
G02B5/00; G02B1/11
Attorney, Agent or Firm:
Takuma Abe
Sogo Kuroiwa
Sogo Kuroiwa