| 摘要 |
PROBLEM TO BE SOLVED: To obtain an optical waveguide type diffraction grating which obviates the occurrence of fracture and disconnection in spite of long-term use and is free of change over aging by using a specific optical waveguide consisting essentially of quartz glass. SOLUTION: This optical waveguide type diffraction grating is constituted by forming a diffraction grating in at least part of the light propagation region of the optical waveguide essentially consisting of the quartz glass. This optical waveguide type diffraction grating is formed by adding >=1 kind of any among elements including P2 O5 , B2 O3 , etc., to at least part of the light propagation region and the absolute value of the dependence of the effective refractive index of the optical waveguide on temp. is <=5.0×10<-6> / deg.C. The core region existing in the central part of the optical fiber of the optical fiber grating which is the diffraction grating formed with the grating in the core region of the optical fiber as the optical waveguide diffraction grating consists of 45 mol.% SiO2 , 10 mol.% GeO2 , 30 mol.% B2 O3 and 15 mol.% P2 O5 and the specific refractive index differenceΔn<+> to the pure SiO2 is +1.3%. |
