COMPOSITIONAL AND STRESS OPTICAL EFFECTS IN GLASS WAVE-GUIDES - COMPARISON BETWEEN K-NA AND AG-NA ION-EXCHANGE

An experimental analysis of the effects of composition, stress and stress relaxation on the refractive index changes in optical waveguides fabricated in soda-lime glass by ion exchange is presented. Stress was determined by waveguide birefringence via analysis of effective modal indices, while compositional profiles are obtained by EDX and RBS measurements. Results are compared for the K+Na+ and for the Ag+Na+ process; it is shown that in soda-lime glass the stress-induced index change is comparable to the compositional term for the K+Na+ process, while for the Ag+Na+ exchange the stress term is much less important and the refractive index change is due only to the compositional term. © 1990.