Abstract

Usually, the elasto-optical coefficients p₁₁, p₁₂,… have to be measured by an optical birefringence interference method associated with an ultrasonic method. By using a laser heterodyning method, one could measure the variations in optical path differences very precisely. Therefore, the variations in the refractive index Δn_e and Δn_o of K-9 glass under 1 atm pressure have been measured directly and precisely to the order of 10^–7. Then the elasto-optical coefficients p₁₁, p₁₂,… have been obtained directly. This technique is very useful for evaluating some kinds of lens design, for instance, the variations of refractive index of a telescope caused by its weight. The dynamic process, the curve of Δn_e and Δn_o via stress, has also been obtained. It shows some interesting results.

© 1992 Optical Society of America