| 摘要 |
PURPOSE:To improve optical propagation efficiency in a prescribed axial direction orthogonal to two axes by forming a coating film, varying in refractive index continuously, in one axial direction on a substrate and by further providing a similar coating film in the other axial direction orthogonal to the said axis. CONSTITUTION:On a substrate 2, a coating film varying in refractive index continuously in a (y)-axial direction is formed to form the 1st optical waveguide 3' and then a removed part 5 is etched away. Over the entire surface including this film surface and the surface where the film on the substrate 2 is removed, a coating film varying in refractive index continuously in an (x)-axial direction is formed to obtain the 2nd optical waveguide 6. Consequently, the center part has minimum refractive index in the (x)- and (y)-axial directions of the optical waveguide and light is confined in the center part, so that an optical thin-film waveguide having excellent propagation efficiency only in the (z)-axial direction is formed. |
