| 摘要 |
PURPOSE:To obtain an optical waveguide having high coupling efficiency with an optical fiber by embedding a high refractive index part formed on the 1st plate into the 1st plate by electric field diffusion. CONSTITUTION:The 2nd plate 7 consisting of the same BK7 glass as a material for the 1st plate 4 is adhered to the 1st plate 4 on which a high refractive index part 6 is formed through glass 8 having a low melting point so that the high refractive index part 6 side is arranged on the adhering side. After forming a thin silver film layer 9, and an anode electrode 10 on the side of the plate 4 and an cathode electrode 10' on the side of the plate 7, these plates 4, 7 are heated at a temp. lower than the glass distortion temp. and an electric field is impressed to permeate the anode ion on the plate 7 into the plate, ionize the silver on the thin film layer 9 and permeate the ionized silver into the plate 4, so that the high refractive index part 6 is pressed into the plate 4. Consequently the high refractive index part 6 having an approximately circular section is formed at the inside of the plate 4. Thus a waveguide having high coupling efficiency can be obtained. |
