Direct measurement of mode hybridization in birefringent slab waveguides by hemisphere m-line ellipsometry
Résumé
The hemisphere m-line technique was used in an ellipsometric configuration to investigate the hybrid waveguide modes of a KTP ion-implanted birefringent planar waveguide. The effective index dispersion as a function of the propagation direction was measured and the polarization angles of the hybrid modes were directly measured for the first time. Special consideration was given to mode crossings in the dispersion diagram. Rotation of up to 3° of the polarization plane of the reflected beam with respect to the incident polarization was investigated. A theoretical model based on the transfer matrix approach was developed and good agreement with experimental results was obtained.