| 摘要 |
PROBLEM TO BE SOLVED: To maximize the transmittance of light of a diffraction grating member having a diffraction grating for splitting light which is formed in the almost same direction as the polarization direction of linearly polarized light as the incident light and which splits the incident light into three directions. SOLUTION: The diffraction grating member (10) is composed of a transparent resin body and has both of an entrance face and an exit face. The diffraction grating (20) for splitting light is formed on one face (15) of the above faces in the almost same direction as the polarization direction of linearly polarized light as the incident light so as to split the incident light into three directions. A diffraction grating (30) for preventing reflection is formed on the other face (16) and the diffraction grating (30) has the grating period smaller than the wavelength of the incident light and the grating direction perpendicular to the direction of the diffraction grating (20) for splitting light. |
