| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a diffraction element capable of being manufactured in a short time, an optical pickup apparatus and an optical disc apparatus. <P>SOLUTION: The diffraction element 10 receives light which has wavelengths λ 1, λ 2 from a light source 20, comprises a first member 13 and a second member 14 which are arrayed alternately in the light entrance surface thereof to constitute a diffraction grating 11 and allows the light having the wavelength λ1 transmitted therethrough and the light having wavelength λ2 separated form and emitted to an optical disc 21. The first member 13 comprises a first resin 15 and exhibits a prescribed refractive index to the light having wavelengths λ1, λ2. The second member 14 comprises a second resin 16 in which a dyestuff 17 is dissolved on the molecular level, absorbs light having a prescribed wavelength range Δλa, and the second member 14 has the same refractive index as that of the first member 13 to the light having the wavelength λ1 and the refractive index different from that of the first member to the light having the wavelength λ2. The maximum absorption wavelength λamax of the light absorbed by the second member 14 is set on outside the wavelengths λ1 and λ2 and the wavelength λa+ at one edge of the wavelength range Δλa is set between the wavelengths λ1 and λ2. <P>COPYRIGHT: (C)2010,JPO&INPIT |
