| 摘要 |
PROBLEM TO BE SOLVED: To provide a wavelength filter used in the telecommunication industry and the electronics industry. SOLUTION: The wavelength filter is of a coincidentally directional optical coupler type, using two or more waveguides with a mutually different refractive index and having a structure formed with a grating (diffraction grating) on the side wall of the waveguides. It is designed to employ a structure with the grating formed on the side wall of the optical waveguide rather than making it an imbedded type with the grating formed inside the face. Therefore, it facilitates modulation of grating amplitude, thereby enabling a variable wavelength filter to be realized that has a high side lobe extinction ratio, a small size and low cost. COPYRIGHT: (C)2006,JPO&NCIPI |
