Birefringence determination in ion-exchanged waveguides

Birefringence as high as 10(-2)divided by 10(-3) in ion-exchanged planar waveguides has been measured by using a double Lloyd's interferometer. Birefringence seems to be produced by the distribution of the mechanical stresses induced during the fabrication process. A new point-by-point calculation to fit the experimental data is proposed which can give new information about the ion-diffusion process and the stress distribution.