| 摘要 |
PURPOSE:To perform light branching which does not depend upon the polarization characteristics of propagating light by combining a phase difference plate and polarized light separating elements. CONSTITUTION:A phase difference plate 21 made of a crystal having the optical anisotropy acting as a 1/2-wavelength plate for the light of a certain lambda1 wavelength, and acting as a 1-wavelength light for another lambda2 wavelength is disposed together with polarized light separating elements 19, 20 and reflection mirros 22, 23. The light of the lambda1 wavelength emitted from an optical fiber 11 is rotated of the plane of linear polarization by 90 deg. by passing the plate 21; therefore, the linearly polarized light parallel to the plane of the figure enters an optical fiber 12 in the route of the element 19, the plate 21, and a polarization prism 20, and the linearly polarized light perpendicular thereto arrives at the fiber 12 similarly in the route of the element 19, the mirror 22, the plate 21, the mirror 23 and the prism 20. Since the light of another lambda2 wavelength is not subjected to rotation of the plane of polarization, the linearly polarized rays parallel and perpendicular to the plane of the figure arrive at an optical fiber 13 respectively in the above-mentioned two routes. |
