| 摘要 |
PURPOSE:To obtain an excellent splitting function without reference to an ellipticity angle by providing a Faraday element which rotates a plane of polarization by 45 deg. and a phase plate which has a phase difference in specific relation with the ellipticity angle. CONSTITUTION:Incident light L1 is passed through a polarizer 16 to become linear polarized light, which is incident on a Faraday rotator 10; and its plane of polarization is rotated by 45 deg. to obtain elliptic polarized light having an ellipticity angle X, which is transmitted through the phase plate 14 having a phase difference delta having relation sindelta>=sin2X with the angle X to becomes linear polarized light, which is transmitted through an analyzer 18 to obtain light L2. Return light L3 obtained by its reflection is passed through an analyzer 18 and the phase plate 14 and made into linear polarized light by the rotator 10, but it crosses the polarization direction of the polarizer 16 and is cut off by the polarizer 16. Thus, the splitting function if made invariably excellent without reference to the ellipticity angle X. |
