PRODUCTION OF OPTICAL WAVEGUIDE TYPE DIFFRACTION GRATING AND OPTICAL WAVEGUIDE FOR ITS PRODUCTION

摘要

PURPOSE: To provide a process for producing a fiber type diffraction grating which increases the reflectivity to the light components of specific wavelengths and a fiber for production of the diffraction grating. CONSTITUTION: An optical fiber 10 is installed in a furnace core tube 20 and gaseous deuterium (D2 ) is made to flow from a valve 21 side toward a valve 22 and a high temp. or high pressure state is maintained in the furnace core tube 20. The optical fiber 10 is an ordinary quarts optical fiber contg. germanium oxide (GeO2 ) in its core part. The heating temp. of the optical fiber 10 is preferably included in a range of 200 to 1300 deg.C. The pressure on the optical fiber 10 is preferably included in a range of 20 to 300atm. The concn. of the deuterium to be added to the core part of the optical fiber 10 is preferably >=500ppm. A great change in refractive index is created in the region to be irradiated with UV light by the reduction treatment of an optical waveguide by the gaseous deuterium and the addition of the deuterium to the core part.