A novel waveguide design for traveling-wave electroabsorption modulators

Abstract: The overall goal of the current thesis addresses the configuration of the waveguide used in Traveling-wave Optical Modulators. In general, our concerns affiliate mostly with achievement of high confinement factor, improved coupling efficiencies and finally single-mode propagation. In principle, waveguides for optical modulators are quite difficult to design entirely, and the usual, and perhaps the most fruitful, approach is to incorporate or slightly modify one of the existing designs. In this sense, we base our structure on the available waveguide, which was already realized in the department, and introduce two etched channels in either side of the mesa structure. From technological point of view, the mentioned fact guarantees the robustness of the novel waveguide for implementation purposes. Meanwhile, we restrict our modifications in a way not to violate the plausible properties of the available guides rather to enhance them more to meet our further expectations. We show that both confinement factor and coupling efficiency can enhance considerably by virtue of these etched channels. Also, it is shown that the novel design renders single-mode propagation structure.