THE MEAN POLARIZABILITY AND DENSITY OF GLASSES

With the combination of the dispersion theory and the Gruneisen consta nt, the frequency- and density-dependence of the mean polarizability o f transparent glasses is discussed. The mean polarizability alpha is f ound to be a function of the density rho of the glass and the angular frequency omega of the incident light. This function is described by a differential equation of partial derivative alpha/partial derivative rho = - [gamma]/rho(2 alpha + omega partial derivative alpha/partial d erivative omega), where [gamma] is the mean Gruneisen constant. At a g iven frequency of the incident light, the mean polarizability is linea rly proportional to the density of the glass. In combination with the Newton-Drude and Lorentz-Lorenz equations, the proposed relationships are used to study the refractive indices of densified SiO2-glasses.