| 摘要 |
PURPOSE:To easily manufacture the variable light wavelength filter at low cost without using any special material by providing two optical waveguides which are formed in a substrate varying in refractive index with temperature and a heater which varies the temperature of an area between those two waveguides. CONSTITUTION:An SiO2 film 4 is formed on the entire surface of the glass substrate 1 and a microheater 5 and electrodes 6 and 6 connected thereto are formed on it. This microheater 5 is positioned right above the area between the coupling parts of the optical waveguides 2 and 3. When a current is supplied between the optical waveguides 2 and 3 to turn on the microheater 5, the temperature of the glass substrate 1 right below it rises, so the refractive index of the area between the optical waveguides 2 and 3 varies and light coupled between the optical waveguides 2 and 3 varies. Consequently, almost all of dielectric materials vary in refractive index with temperature, so glass and other materials are usable as the substrate material and the variable light wavelength filter is easily manufactured at low cost. |
