Resumen de Photonic applications based on bimodal interferometry in periodic integrated waveguides
Silicon photonics is a key emerging technology in next-generation communication networks and data centers interconnects, among others. Its success relies on the ability of using CMOS-compatible platforms for the integration of optical circuits into small devices for a large-scale production at low-cost. Within this field, integrated interferometers play a crucial role in the development of several on-chip photonic applications such as biological sensors, electro-optic modulators, all-optical switches, programmable circuits or LiDAR systems, among others. However, it is well known that optical interferometry usually requires very long interaction paths, which hinders its integration in highly compact footprints. To mitigate some of these size limitations, several approaches emerged including sophisticated materials or more complex structures, which, in principle, reduced the design area but at the expense of increasing fabrication process steps and cost.
This thesis aims at providing general solutions to the long-standing size problem typical of optical integrated interferometers, in order to enable the densely integration of silicon-based devices. To this end, we combine the benefits from both bimodal waveguides and periodic structures, in terms of high-performance operation and compactness to design single-channel interferometers in very reduced areas. More specifically, we investigate the dispersive effects that arise from subwavelength grating and photonic crystal structures for their implementation in different bimodal interferometric configurations. Furthermore, we demonstrate various potential applications such as sensors, modulators and switches in ultra-compact footprints of a few square microns. In general, this thesis proposes a new concept of integrated interferometer that addresses the size requirements of current photonics and open up new avenues for future bimodal-operation-based devices.
