Patent ID: 6580854
Filing Date: 2003-06-17
Classification: G02B

Abstract:
An optical waveguide grating which is formed in an optical waveguide mainly composed of SiO2 and having a core region and a cladding region around said core region, said grating being formed by providing said core region with an area in which a refractive index thereof changes periodically in the direction of its optical axis so as to form a long-period grating, wherein said core region is co-doped with GeO2 and P2O5, and the ratio of molar doping amount of P2O5 and GeO2 is adjusted for controlling temperature dependence of the loss peak wavelength, whereinsaid cladding region is doped with fluorine and has a refractive index adjusted so as to be lower than that of pure silica glass; and wherein letting &Dgr;nâˆ’ be the ratio of decrease in refractive index of said cladding region with respect to pure silica glass, the molar doping amount of P2O5 in said core region is adjusted within the range of (0.8-0.7 &Dgr;nâˆ’)Â±0.2 times that of GeO2.