光学ガラスヤケの研究SiO2の影響 (II)
1959 年 28 巻 9 号 p. 539-544
詳細
1959 年 28 巻 9 号 p. 539-544
The growth of low refractive index layer (L. I. layer) on the surface of optical grass in SiO2-water or alkali solution is studied in detail.
The amount of glass dissolved is measured by multiple beam interferometry. The thickness (d) and the refractive index (n) of the layer are measured by polarimetric method.
In the cases of SK 16 and SSK 5, thick growth of L. I. layer is observed in SiO2-water solution.
SF 3 and BK 7 are hardly affected by the presence of SiO2 in neutral solution. But in con-centrated SiO2-alkali solution the growth of L. I. layer is observed on the surface of BK 7 as well as SF 3.
BK 7 is a durable glass against acids and alkalis. The largest thickness of the L. I. layer observed is about 600 A. A definite value of the refractive index of the surface layer on BK 7 is not obtained. In this case, the growth of L. I. layer is expressed by the fall of the refractive index of the layer together with the thickness.
