| 摘要 |
PURPOSE:To precisely control the sectional shape and dimensions of a core part and control the refractive index with high accuracy by forming a transparent glass layer on a glass substrate with grooves for the core part formed, removing the layer except the core part, and forming a transparent glass layer. CONSTITUTION:Thick metallic film 6 is formed on the smooth surface of glass substrate 5 and etched after a desired pattern. Using this film 6 as a mask substrate 5 is subjected to reactive sputter etching to form grooves for a core part, and residual film 6 is removed. Substrate 5 is then put in a reactor, and by feeding Si, Ge, P, B and Ti halides and O2 or steam, glass fine particle layer 7 is deposited and converted into transparent glass layer 8 by heating. After removing layer 8 except glass for the core part by etching, substrate 5 is put in a reactor, and by introducing Si, Ge, P, B and Ti halides, fluorides and O2, glass fine particle layer 9 is deposited and heated to form transparent glass layer 10. |
