PhD defence by Yaoqin Lu

Abstract

In recent years, wide bandgap semiconductors like Silicon Carbide (SiC), Gallium Nitride, Lithium Niobate, and Aluminum Nitride have gained researchers’ interest in integrated photonics due to their ability to transmit a broad range of light wavelengths with minimal nonlinear propagation losses. Among these, SiC is particularly notable for its excellent optical properties, making it valuable for both classical and quantum optics.

In integrated photonics, researches have predominantly focused on crystalline formsof SiC, but these materials present challenges for large-scale, commercially viableimplementations on SiC-on-insulator platforms. This thesis explores the potential of amorphous SiC (a-SiC), which can be more easily deposited on substrates. The study investigates the application of a-SiC in integrated photonics, with a focus on developing devices on an a-SiC-on-insulator-platform (a-SiCOI). It explores the third-order nonlinearity and thermo-optic effects in this material, showcasing various devices, including couplers, microring resonators, photonic crystal waveguides, and thermooptic modulators.

This research opens up new avenues for using a-SiC in a wide range of photonic applications, positioning it as a promising material for future innovations in the field.

Supervisors

• Main Supervisor: Associate Professor Haiyan Ou, DTU Electro, Denmark
• Co-supervisor: Professor Karsten Rottwitt, DTU Electro, Denmark

Assessment committee

• Senior Scientist, Stela Canulescu, DTU Electro, Denmark (chair)
• Francesco La Via, Research Director, CNR-IMM sede di Catania, Italy
• Manager Lars Hagedorn Frandsen, NIL Technology, Denmark

Master of the Ceremony

• Professor Paul Michael Petersen, DTU Electro, Denmark