| 摘要 |
PROBLEM TO BE SOLVED: To constitute an optical waveguide type polarizer while hardly disturbing the crystalline structure of a substrate by adding a first ion having a smaller ion radius than Nb ion to a substrate to constitute an optical waveguide and adding a second ton having a larger ton radius than the first ion to induce a polarizing effect. SOLUTION: On a substrate 1 comprising lithium niobate, an optical waveguide part 2 is formed into a desired waveguide pattern by using a material containing a first ion having a smaller ion radius than the Nb(+5) ion, and further, an auxiliary optical waveguide part 3 is formed in contact with the optical waveguide part 2 by using a material containing a second ion having a larger ion radius than the first ion. As for the first ion, Ti ion (having 0.605Å ion radius against 0.64 A ion radius of Nb ion) is used. As for the second ion, Ni ion (having 0.69Å ton radius) is used. For example, the optical waveguide part 2 with addition of Ti ion and the auxiliary optical waveguide part 3 with addition of Ni ion adjacent to both sides of the waveguide part 2 are formed on the lithium niobate substrate 1. |
