| 摘要 |
PROBLEM TO BE SOLVED: To inexpensively and easily form a grating with good accuracy at a desired submicron period without dependence upon polarization in an optical waveguide of an ion exchange type. SOLUTION: Portions where metal ions are deposited in a colloidal state and portions where the metal ions exist in the state of an ion state are arrayed alternately periodically in the ion exchange type optical waveguide formed in a glass substrate, by which refractive index changes are generated at a specified period. The metallic particulates deposited in the colloidal state are formed Ag colloid. The period of the refractive index changes is preferably specified to 0.2 to about 1.0μm. The entire part is irradiated with the light of low-irradiation intensity to deposite the metal ions in the colloidal state and is then locally irradiated with the light of high-irradiation intensity at a desired period to eliminate the deposition. Otherwise, the portions are locally irradiated with the light of low-irradiation intensity at a desired period to deposite the metal ions in the colloidal state. As a result, the deposited portions and the portions in the state of the ion state are alternately periodically formed to give rise to the refractive index changes. |
