| 摘要 |
PURPOSE:To suppress the crosstalk by inter-channel interference between wavelengths by providing a resistance layer on or in a substrate and laminating a low-refractive index layer, core waveguide and clad layer successively thereon, then impressing voltage across this resistance layer. CONSTITUTION:The resistance layer 200 is formed only in the region of the substrate 100 shown by the broken line in the figure. A high-concn. layer is formed in parts 11, 12 where electrodes of heating elements are to be formed. A film 300 is deposited atop the substrate 100 and light guides 400, 401 are formed thereto. The entire part is enclosed by a clad layer 500. Through-holes are formed to the required parts where the surface is to be exposed in order to draw the electrodes out of the heating elements, then the electrodes 13, 14 are formed. The control of the central wavelength of the spectral characteristics by changing the temp. is, therefore, possible by passing the current to the resistance layer 200. The crosstalk by the inter-channel interference between the wavelengths of the light signals is thereby suppressed. |
