NONLINEAR TOTALLY REFLECTING PRISM COUPLER - THERMOMECHANIC EFFECTS AND INTENSITY-DEPENDENT REFRACTIVE-INDEX OF THIN-FILMS

Starting with an accurate linear electromagnetic theory of a totally r eflecting prism coupled to a dielectric waveguide, we implement a nume rical technique to take into account optogeometric perturbations in st ratified media. We calculate both the reflected fields in intensity on the prism base (near field) and in infinity (far field) for an incide nt Gaussian beam. The study of the variations of the intensity in the reflected beam (near and far fields) versus light power shows thermoin duced dilation of the prism and an intensity-dependent refractive inde x of thin films composed of tantalium pentoxyde and titanium dioxide.