| 摘要 |
PROBLEM TO BE SOLVED: To provide a polarized light separating element performing polarized light separation with high efficiency and high reliability, with compact constitution and without causing heat generation due to absorption. SOLUTION: A diffraction grating 4 is formed on a boundary between a birefringent medium 1 and a first glass prism 2. Since the refractive index of the first glass prism 2 is equal to the normal light refractive index or the abnormal light refractive index of the birefringent medium 1, though a linear polarization component causing a refractive index difference at the diffraction grating 4 is diffracted in the light made incident on the birefringent medium 1, the linear polarization component orthogonally intersecting with it is not diffracted since the refractive index difference is caused, and the incident light is separated. Further, an air layer 5 is provided between the first glass prism 2 and a second glass prism 3, and the angle is decided so as to totally reflect only the light diffracted by the diffraction grating 4. By such a constitution, two polarization light beams are separated effectively.
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