Microwave characteristics of planar electrooptic modulator

An attempt is made to model traveling-wave optical modulators in the microwave frequency range by two methods: a desktop computer method based on the effective complex dielectric constant and a more rigorous method, i.e. the mode-matching technique. The aim is to quantify both bulk microwave and metallic losses and to determine the phase velocity in the microwave frequency range. This study takes into account the geometry of the cross section of the structure, the multilayered nature of the waveguide, and the hybrid nature of the mode. The two methods are compared for moderately lossy structures and shown to give quite similar results. However, when more realistic structures with highly doped multilayered substrates are considered, only the rigorous method can be used.<>