| 摘要 |
PURPOSE: To lessen transmission loss by smoothing the ruggedness of the side walls of a channel type optical waveguide. CONSTITUTION: This channel type optical waveguide is obtd. by etching from a slab type waveguide composed of a substrate 4, an under clad layer 3, a core layer 1 and an overclad layer 2. The waveguide 13 having the smooth side walls is formed by immersing the side walls 12 having the ruggedness into a soln. prepd. by dissolving a core material. The channel type optical waveguide is immersed into the soln. prepd. by dissolving the core material into a solvent dissolving the core material so as to attain a suitable concn. After the skin layer of the specified quantity is dissolved, the waveguide is pulled up from the soln. and is dried, by which the waveguide surface is freshly coated with the core material and the smooth waveguide side walls are obtd. The thickness of the core layer removed during immersing is determined by the dissolution rate with the soln. of the material and is, therefore, controllable by the immersion time. The coating film thickness after the pulling up is controlled by the pulling up speed, the viscosity (dependent upon the concn.) of the soln., temp. and drying conditions. |
