Effect of glass composition on silver-incorporation into aluminoborosilicate glasses through a staining process

Abstract

To fabricate graded-index optical elements by silver staining, we investigated the behavior of ion incorporation in aluminoborosilicate glasses, in which the contents of Al2O3 and Na2O were the same (in mol%). The amount of silver incorporated into the aluminoborosilicate glasses by the staining at 320 °C for 12 h was 5 to 10 times larger than that incorporated into the soda-lime silicate and borosilicate glasses. The diffusion depth of the incorporated silver ions was approximately 80 μm, which was also much deeper than that of the soda-lime silicate and borosilicate glasses. The coloration of the glasses was suppressed, particularly for the glass with the low content of Na2O. The concentration of the incorporated silver ions at the glass surface was 2 × 1021 atom/cm3 for the 37.5SiO2·25Al2O3·25Na2O·12.5B2O3 glass, corresponding to the replacement of sodium ions (20%). The refractive indices near the stained surfaces increased by 0.04 to 0.06. These values were comparable with those of the soda-lime silicate and borosilicate glasses.