Data are presented on the changes in the room-temperature refractive index and density of a borosilicate crown glass produced by different heat-treatments. Measurements on a large number of samples with widely varying thermal history show that the refractive index is a single-valued function of the density. The increase in refractive index for a given density change is smaller than that calculated by the Lorentz-Lorenz theory; the apparent contribution of the induced polarization to the local electric field is very small. This may be due to a reduction in the ionic polarizabilities that accompany the density increase; alternatively, the Lorentz-Lorenz form of the theory may not be valid in solid materials such as glass. Data of other investigators are shown to agree with the data reported here.
Moderation Team
![[Post New]](/templates/default/images/icon_minipost_new.gif){kind=icon}
![[Up]](/templates/default/images/icon_up.gif "[Up]"){kind=icon}
76
1
