| 摘要 |
PURPOSE:To make an optical waveguide stable thermally and mechanically and low in loss and to improve the coupling efficiency thereof to optical fibers by forming said waveguide into a sectional shape of roughly a circular shape. CONSTITUTION:When a substrate 4 provided with a thin film layer 1 of aluminum, a thin film layer 2 of silver, an anode electrode 3 consisting of chromium and a cathode electrode 3' of aluminum by vacuum deposition is heated to glass deforming temp. or below with a heater 5 and the respective electrodes are removed after applying an electric field thereto the diffuse silver ions into the substrate 4, a high refractive index part 6 having a section of a semicircular shape is formed in the substrate 4. The substrate 4, and a substrate 7 contg. a thin film layer 9 of silver and an anode electrode 10 consisting of chromium are press stuck by using jigs 8 for press sticking in such a way that the cathode 10 and the anode 10 are located mutually on the outer sides. Both substrates are heated, and an electric field is applied thereto to force the part 6 into the substrate 4. At the same time, the silver of the layer 9 is ionized and is penetrated into the substrate 7. As a result, the high refractive index part 6' having a sectional shape of a roughly circular shape is obtained in the substrate 4, and said part acts as an optical waveguide. |
