| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical waveguide with a grating which hardly causes a wavelength shift even when ambient temperature rises and has high diffraction efficiency and optical transmission efficiency. SOLUTION: The optical waveguide formed by laminating a lower clad (3D), a core (4), and an upper clad (3U) on a substrate (2) in this order has at least one thin-film type grating layer (5) formed on the core (4) along its length direction. COPYRIGHT: (C)2004,JPO |
