| 摘要 |
PURPOSE:To obtain an optical attenuator which is free from difficulty of optical axis alignment for production and is easily miniaturized and has a high mechanical stability, by providing two curved waveguides different in curvature radius formed on the surface of a substrate and a pair of optical switches which select one of these waveguides. CONSTITUTION:A waveguide 2 which is unified in one end and is branched into two twice to go to four curved waveguide parts 21-24 and is coupled twice to be unified in the other end is formed on the surface of a substrate 1. Curved waveguide parts 21-24 are formed on concentric circles so that they are different in curvature radius, and the waveguide loss is different by each curvature radius. Electrodes 3 are formed in respective Y-shaped branch parts to form Y branch optical switches which use the electrooptic effect due to voltage application to electrodes 3, and either of curved waveguides is selected by the switch in each Y-shaped branch part to select one of four curved waveguide parts 21-24. |
