| 摘要 |
PURPOSE:To minimize bias variation due to reflected light on an end surface connected to an optical propagation path by providing a reflection coefficient equal to that of a conventional optical waveguide phase modulator and giving an optical path difference between reflected light beams on the end surface connected to the optical propagation path when a 1st and a 2nd light beam are projected on the optical propagation path. CONSTITUTION:In the optical propagation path coupled optically with the optical fiber coil, an incident light beam is distributed as the 1st and 2nd light beams which prescribe both directions and light beams which are propagated in the optical fiber coil in both directions are coupled with an optical distribution and coupling part. When the 1st and 2nd light beams are projected on the side of the optical propagation path, the optical path difference is given between the respective reflected light beams B1 on the end surface 11 connected to the optical propagation path. Consequently, the bias variation due to the reflected light beams on the end surface 11 connected to the optical propagation path is made narrow. |
