| 摘要 |
PURPOSE:To measure PDL with high accuracy by preventing a measured value from being affected by the output fluctuations of a light source and the fluctuations of the quantity of the light transmitting through a polymarization controller and reducing the measuring error caused by the polarization dependence of the sensitivity of a photodetector to a large extent. CONSTITUTION:The light emitted from a light source 1 is allowed to be incident on a light branching device 3 while the polarization state thereof is controlled by a polarization controller 2 and the outputs from all of the emitting ports 3a, 3b of the light branching device 3 are respectively measured by photodetectors 4, 5 and the degree of coupling of the respective emitting ports 3a, 3b is calculated from the measured values thereof and the polarization dependence of transmission loss is calculated from the fluctuations of the degree of coupling obtained when the polarization state is changed. |
