Open AccessThe photo-elastic dispersion of vitreous silica
Author(s) -
L. N. G. Filon,
Frank Harris
Publication year - 1931
Publication title -
proceedings of the royal society of london. series a, containing papers of a mathematical and physical character
Language(s) - English
Resource type - Journals
eISSN - 2053-9150
pISSN - 0950-1207
DOI - 10.1098/rspa.1931.0014
Subject(s) - refraction , dispersion (optics) , refractive index , materials science , isotropy , composite material , optics , creep , optoelectronics , physics
1. The dispersion of the double refraction induced by stress in isotropic transparent substances has been the subject of a number of investigations. All of these, however, have dealt with compound substances, such as ordinary glasses and nitro-cellulose. It appeared of interest to obtain data, as accurate as possible, for a substance of glassy type, containing only a single chemical constituent, and in which the complications arising from progessive creep (such as occurs in nitro-cellulose and gelatine) were absent. Vitreous silica provides such a material and is now obtainable in fair-sized blocks of good optical quality. 2. Two rectangular blocks of vitreous silica were obtained from the Thermal Syndicate, Ltd. Their dimensions were as follows:a (the height) being parallel to the line of stress,b (the height) being at right angles to both the line of stress and the rays of light, andd (the thickness) being in the direction of travel of the light through the block:- A.a = 2.142,b = 0.467,d = 0.902. B.a = 4.270,b = 1.228,d = 3.250.