| 摘要 |
PURPOSE:To adjust the doubly refractive main axis of a constant polarization fiber so as to keep it in a fixed direction on the basis of the detected result of said main axis by making light incident on the fiber and detecting its transmitted light. CONSTITUTION:Light projected from a light source 11 is made linearly polarized light through a polarizing plate 12 and then made circularly polarized light through a lambda/4 plate 13 and the circularly polarized parallel light is made incident from the side of a bobbin 18. A mirror 14 set up with 45 deg. angle from the incident parallel light is arranged on the center of the bobbin 18 and the light reflected by the mirror 14 is made linearly polarized light through a lambda/4 plate 15, stopped by a lens 16 and then made incident on a constant polarization fiber 17. Therefore, the linearly polarized light can be made incident from the lower port of the constant polarization fiber wound around the rotating bobbin 18. To detect the light transmitted from the lower port of the winding bobbin 18, the doubly refractive main axis of the constant polarization fiber can be detected by incorporating a detector to the inside of the bobbin similarly to said procedure or guiding light to the outside to detect it with the same constitution. |
