| 摘要 |
PURPOSE:To eliminate the dependency on the polarization state of incident light, to lower a switch voltage, and to facilitate formation by providing a 3rd control electrode nearby two close optical waveguides and opposite either of 1st and 2nd control electrodes installed on the two optical waveguides. CONSTITUTION:The 1st and 2nd control electrodes 15 and 19 are installed on the optical waveguides 12 and 13 and further the 3rd control electrode 20 is provided opposite the control electrode 19 and nearby the optical waveguide 13. The length of an optical directional coupler 14 is set nearly to complete coupling length for both TM and TE modes as usual. Thus, the 3rd control electrode is installed to approximate the quantities of refractive index variation for both TM and TE modes by utilizing electric field components in two mutually orthogonal directions effectively, and the switch voltage is further lowered. |
