| 摘要 |
PROBLEM TO BE SOLVED: To provide a waveguide which is formed by adding fluorine to a core having a waveguide of a high specific refractive index differenceΔ, is substantially free of absorption peaks from a wavelength 1.3μm band to a wavelength 1.6μm band, is extremely low in loss and facilitate refractive index control and a process for producing the same. SOLUTION: When the fluorine is added into the core of an oxide co-added with at least one kind of additives to enhance the refractive index, the hydrogen of the OH group, Si-H group or N-H group and fluorine existing in the clad layer 21 and the core 22 react to form gaseous HF which may be released outside the core 22. Consequently, the core 22 substantially free of the OH group, Si-H group or N-H group may be embodied. As a result, the waveguide which is extremely low in loss is obtd. As the amt. of the fluorine to be added into the core 22 is larger, the effect is higher. If the fluorine is added into the intermediate layer and the clad layer 21 as well, the waveguide having the lower loss is obtd. |
