| 摘要 |
PURPOSE:To effectively prevent occurrence of crack in mask boundary part in cooling treatment of a glass substrate and contrive high accuracy, by using a Tl-containing mixed salt as a melted salt in production of an optical waveguide. CONSTITUTION:A mixed salt consisting of 10-80mol% Tl2SO4 and/or 0-45mol% and 5-90mol% either one of HgSO4, NiSO4 or CdSO4 is melted to provide a melted salt. Then surface part corresponding to required optical waveguide is brought into contact with the above-mentioned melted salt containing Tl and Tl ion is diffused into the interior of glass and part having high reflex index is formed to produce the optical waveguide. |
