| 摘要 |
PROBLEM TO BE SOLVED: To make the polarization dependency dissoluble in the composite spectral characteristics of an optionally designed array waveguide type diffraction grating, by providing an ion-implated layer at a core bottom face part using an ion implantation. SOLUTION: After a lower clad layer 2 is provided on a plane substrate 1, an ion-implanted layer 3 is formed on the lower clad layer 2 by an ion implantation. After a core layer 4 is provided on the ion-implanted layer 3, a core part 5 is formed by etching, and an upper clad layer 6 is formed on the ion- implanted layer 3 and the ore part 5 to embed the core part 5. The change of the stress field near core glass or the change of a refractive index of the ion implanted layer 3 is therefore induced to obtain an optical waveguide and optical parts with polarization dependency. Since the ion implanted layer 3 is formed being embedded in glass, nonpolarizing action can be maintained semipermanently. Furthermore, since the ion implanted layer 3 formed by the ion-implantation is optically homogeneous glass, there is no possibility of the ion implanted layer 3 causing the loss and extinction ratio degradation of the optical waveguide. |
