Development of new photonic devices based on barium titanate in silicon

Resumen

Integration of complex optical functionalities with high performance will lead to a huge development in the field of nanophotonics for a broad range of applications. Silicon photonics is currently the leading technology for the implementation of low-cost photonic integrated devices. The great potential of this technology relies on its compatibility with the mature silicon integrated circuits manufacturing based on complementary metal-oxide semiconductor (CMOS) processes widely used in microelectronic industry and the availability of high quality silicon-on-insulator wafers, an ideal platform for creating planar waveguide circuits that offers strong optical confinement due to the high index contrast between silicon (n=3.45) and silicon dioxide (n=1.45). In order to keep improving the performance of photonic devices on silicon, the integration of CMOS compatible materials with unique properties shows up as an excellent opportunity to overcome the current limitations in silicon while offering unprecedented and novel capabilities to the silicon platform. In this way, barium titantate (BaTiO3) stands out as one of the most disruptive candidates. The work developed in this thesis is essentially focused on the design, fabrication and characterization of an electro-optic modulator based on a hybrid BaTiO3 on silicon structure for the implementation of high performance electro-optic functionalities with beyond state-of-the art performance that currently cannot be afforded in silicon photonics technology.