| 摘要 |
PROBLEM TO BE SOLVED: To provide a waveguide-type polarizer capable of stably adding the function of a polarizer to an optical waveguide without using a special manufacturing step.SOLUTION: In the waveguide-type polarizer including a Z-cut lithium niobate substrate 1, and an optical waveguide having a ridge structure that is formed on the substrate, the width of the ridge structure is a ridge width where the distribution of ordinary light of light waves propagated through an optical waveguide changes, and the distribution of extraordinary light of the light waves does not change, the angle of the ridge structure is less than 90°. Then, a low refractive index film 3 having a thickness satisfying a condition of 0≤n×t/λ≤0.3742 (where n is a refractive index, t(μm) is the thickness of the film, and λ(μm) is the wavelength of the light wave) is formed on the side of the ridge structure, and a high refractive index film 4 having a thickness satisfying a condition of 0.089≤n×t/λ is formed on the low refractive index film, whereby the waveguide-type polarizer has a function of extraordinary light transmission polarizer. |
