Abstract: An optical waveguide element that can stably and inexpensively form an optical waveguide of low loss and low stress in a glass material by ion exchange of Ag ions, and to provide a process for producing the same are provided. The optical waveguide element is made of a multicomponent glass material, which is Na2O—B2O3—Al2O3—SiO2 glass containing from 5 to 13% by mole of Na2O, in which an optical waveguide is formed by doping with Ag ions by ion exchange. The composition is preferably SiO2: 60 to 75% by mole, B2O3: 10 to 20% by mole, Al2O3: 2 to 10% by mole, Na2O: 5 to 13% by mole, Li2O: 0 to 1% by mole, As2O3: 0 to 0.5% by mole, and Sb2O3: 0 to 0.5% by mole (provided that As2O3+Sb2O3: 0.01 to 1% mole).

Abstract: An optical waveguide element that can stably and inexpensively form an optical waveguide of low loss and low stress in a glass material by ion exchange of Ag ions, and to provide a process for producing the same are provided. The invention provides an optical waveguide element comprising a multicomponent glass material, which is Na2O-B2O3-Al2O3-SiO2 glass containing from 5 to 13% by mole of Na2O, in which an optical waveguide is formed by doping with Ag ions by ion exchange. The composition is preferably SiO2: 60 to 75% by mole, B2O3: 10 to 20% by mole, Al2O3: 2 to 10% by mole, Na2O: 5 to 13% by mole, Li2O: O to 1% by mole, As2O3: O to 0.5% by mole, and Sb2O3: O to 0.5% by mole (provided that As2O3 +Sb2O3: 0.01 to 1% mole).