| 摘要 |
PURPOSE:To form an optical waveguide having a decreased light loss and excellent transmission characteristic by depositing an optical waveguide layer on a substrate, patterning said layer to the shape of the prescribed optical waveguide and subjecting the surface of the optical waveguides to a melting treatment by heating the same up to the temp. slightly higher than the m.p. of the optical waveguide layer. CONSTITUTION:After the optical waveguide layer 2 is patterned to the shape of the prescribed optical waveguides, the surface of the waveguides 2 is subjected to the melting treatment by heating the same to the temp. slightly higher than the m.p. of the waveguide layer 2. Such melting treatment is simply required to be executed by heating the waveguides 2 for about 20sec at 600-700 deg.C then slowly cooling the same at such a rate at which the substrate 1 and the waveguides 2 do not receive thermal impact in the case of forming the waveguides 2 of, for example, PbO-SiO2 and by slowly heating the waveguides for about 20sec at about 1,200 deg.C then slowly cooling the same at such a rate at which the substrate and waveguides do not receive the thermal impact in the case of forming the waveguides of GeO2-SiO2. The surface of the waveguides 2 is thereby melted to a semi-cylindrical sectional shape having the dull angle parts. The numerous microflaws generated on the surface in an etching stage are repaired by surface tension, by which the transmission loss of light is considerably decreased. |
