ABSTRACT
K, = dn,/dP, where the ordinary and extraordinary indices of refractive are designated ns and np, respectively, according as the light polarization is perpendicular (s) or parallel (p) to the pressure vector. The elastooptic coefficients can be calculated from the experimentally determined values of the stress optic coefficients through the relations
p11 = 2E[2J.1K, + (1-J.1)Kr]/[n\2}l-1)(J.1 + 1)] and
p12 = 2E[J.1Kr + K,]/[n\2}l-1)(J.1 + 1)], where E is the elastic modulus and J.1 is Poisson's ratio.
