| 摘要 |
PURPOSE:To facilitate formation of an array by permitting a refractive index distribution type lens to lower in refractive index gradually as the distance from an optical axis increases. CONSTITUTION:A salt 10 composed of Tl2SO4, ZnSO4, and K2SO4 and an anode platinum electrode 11 are placed on a magnetic boat 9, and a box type cell 13 having a bottom of a flat plate glass 12 where the diffusion of Tl<+> ion is performed is constructed by hot pressing or joining these flat glass plates 13 by welding or sticking. A metallic mask 14 having proper openings is formed on the surface of the glass 13, and this mask has an effect of intercepting implantation of metal ions into the inside of the glass and allows the metal ions to implant only through the openings of the mask 14. A cathode platinum plate 15 and a salt 16 composed of Tl2SO4, Na2SO4, and K2SO4 are placed in the cell 13, and the cell 13 is set above the anode 11. The boat 9 is heated to 500-600 deg.C in this state, after melting the salts 10, 16, and several V/mm. DC voltage is impressed between the electrodes 11, 15. After a prescribed time length, the molten salts are removed, and after cooling, it is washed with warm water, and the mask 14 is removed. |
