| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an optical switch which uses a quartz light waveguide and can be used in a wide wavelength band useful for a light wavelength multi ple transmission. SOLUTION: The optical switch is the quartz waveguide and comprises a Y branching waveguide and a directional coupler 7 coupled to the Y branching waveguide. The directional coupler 7 comprises two waveguides 12C, 12D having different widths of cores. An interval between the waveguides is gradually widened. A metal thin film heater is installed on an overclad having a large interval between the waveguides. The width of the core of one waveguide is smaller than widths of an entrance and an exit of the directional coupler 7. The width of the core of another waveguide is larger than the widths of the entrance and exit.</p> |
