| 摘要 |
An optical waveguide which can suppress adjacent crosstalk even when wavelength intervals to be multiplexed/demultiplexed are narrow. A lower clad film and a core film are deposited and formed on a substrate (11) by flame hydrolysis deposition, and they are consolidated, whereupon the core film is processed into a waveguide pattern. The waveguide pattern is formed by successively connecting at least one optical input waveguide (12), a first slab waveguide (13), an arrayed waveguide (14) consisting of a plurality of channel waveguides (14a) arranged side by side and having lengths different from one another, a second slab waveguide (15), and a plurality of light output waveguides (16) arranged side by side. The waveguides arranged side by side are at intervals from one another. An upper clad film covering the waveguide pattern is deposited and formed by flame hydrolysis deposition, and it is thereafter consolidated. Herein, a sintering rate in a temperature rise from a temperature at which the density change of the glass particles of the upper clad film starts, to a temperature at which the density change ends, is set at 1.0° C./min or below at the step of consolidating the upper clad film, whereby the arrayal aspect of the channel waveguides (14a) is brought close to an ideal aspect.
|
