Photoelastic Behavior of Rochelle Salt

All 12 stress-optic constants and all 12 strain-optic constants of Rochelle salt have been determined for the first time, by employing different experimental techniques at the different stages of the investigations. The values of qᵢⱼ and pᵢⱼ for the sodium yellow light at room temperature (27^∘{}C) are as follows: all in units of 10^-13 cm²/dyn; The values inside the parentheses are those obtained by Pockels, and indicate only the orders of magnitude.