PURPOSE: To provide optical waveguide type diffraction gratings which are less changed 10 Bragg wavelength and have high reliability despite of a change in the temp. of an atmosphere where the optical waveguide type diffraction grating is installed and a change in the temp. of the diffraction gratings themselves.
CONSTITUTION: The optical waveguide type diffraction gratings 43, 44 have cores 41 which are optical waveguide parts contg. germanium oxide and clads 43 which have the refractive index lower than the refractive index of these cores 41 in contact with the cores 41. These diffraction gratings include titanium oxide in the cores 41 or the clads 42. The process for producing the optical waveguide type diffraction gratings 43, 44 include a first stage of preparing glass optical waveguides including the titanium oxide in the cores 41 or the clads 42 and a second stage for changing the refractive index by subjecting the plural prescribed parts of the cores 41 and clads 42 of the glass optical waveguides to irradiation 10, 11, 20, 30 with UV rays.
INOUE SUSUMU
ITO MASUMI
