| 摘要 |
<P>PROBLEM TO BE SOLVED: To enhance the durability of an optical element whose optical action differs due to a wavelength. <P>SOLUTION: In the optical element having an optical member transmitting light, a first material layer formed on the surface of the optical member and a second material layer formed on the first material layer, a Fresnel lens, a diffraction structure or a rugged structure is formed on a boundary surface between the first material layer and the second material layer, and both the first material layer and the second material layer are formed by inorganic material. A difference between the refraction index of the first material layer and the refraction index of the second material layer satisfies (λ<SB POS="POST">B</SB>Δn<SB POS="POST">A</SB>/λ<SB POS="POST">A</SB>Δn<SB POS="POST">B</SB>)≥5 in the case that a refraction index difference Δn<SB POS="POST">A</SB>in the light of the wavelength λ<SB POS="POST">A</SB>of 1 among light of the wavelength of 390 to 830 nm is 0.05 or more and a refraction index difference in the light of the other wavelength λ<SB POS="POST">B</SB>is defined as Δn<SB POS="POST">B</SB>. The light of the other wavelength λ<SB POS="POST">B</SB>is light of the wavelength of 1 or 2, and transmittance in the light of the wavelength between 390 to 830 nm is 50% or more. <P>COPYRIGHT: (C)2013,JPO&INPIT |
