Photoelastic Constants of Ruby

The eight piezo-optic and eight elasto-optic constants of synthetic, single crystal ruby have been determined using the cadmium red radiation of 643.8 nanometers (nm). All the constants are found to be negative in value, or to have very small positive values. The data indicate that changes in the polarizability of the oxygen ion and changes in the local field are primarily responsible for the observed changes in refractive index. Hydrostatic pressure has been used for the first time as part of a complete photoelastic investigation, and a new, screw-clamp device for easily attaining high, uniaxial stress is described.