| 摘要 |
PROBLEM TO BE SOLVED: To provide a process for producing an optical waveguide capable of enhancing the adhesion property of an upper clad layer to a core and lower clad layer, etc., without adversely affecting the core, the lower clad layer, etc. SOLUTION: The lower clad layer 3 is deposited by using a plasma enhanced vapor deposition method on a substrate 4 (stage 1). After the core layer 1' is formed on the lower clad layer 3, the unnecessary part of the core layer 1' is removed and the core 1 is formed (stage 2). The upper clad layer 2 is deposited by an ionization vapor deposition method by using a material for vapor deposition prepd. by using silicon dioxide as an essential component and mixing phosphorus pentoxide and boron oxide therewith (stage 3). The contents of the phosphorus pentoxide and boron oxide in the material for vapor deposition are made equal. The material is thereafter subjected to a heat treatment for a prescribed time. The material for ion vapor deposition contg. the material having the m.p. lower than the m.p. of the silicon dioxide is used, by which the upper clad layer 2 is melted at the temp. lower than the m.p. of the pure silicon dioxide in the heat treatment after the execution of the deposition by the ionization vapor deposition. The adhesion property of the upper clad layer 2 to the lower clad layer 3 and the core 1 surface is thus improved. |
