Integrated Microring Resonator: From Light Coupling to Photonic Signal Processing

Photonic signal processing offers an intriguing opportunity to handle the ultra-high frequency signals, especially for microwave signal, due to its advantages of multi-gigahertz sampling frequency, high time-bandwidth product and immunity to Electromagnetic Interference (EMI). Among many photonic sub-components, one of the essential parts for implementing photonic signal processing is Microring Resonator (MRR) which provides compact solution towards high-density packing of Photonic Integrated Circuit (PIC). With the on-chip micro-heater, the tunability and reconfigurability are achieved. To facilitate design and modelling, the thesis starts with the analysis of the basic building blocks on the Silicon-On-Insulator (SOI) and Silicon Nitride (Si3N4) platforms. In this thesis, the reconfigurable integrated optical switch is proposed based on eye-like resonator structure with tunable Electromagnetically Induced Transparency (EIT)-like transmission profile. This device is beneficial to various on-chip applications, such as phased-array-antenna-based beamforming technique, Light Detection and Raging System (LIDAR), Photonic Radio Frequency Memory (PRFM), and photonic interconnect. As the Si3N4 platform provides the low-loss alternative to the SOI technology, the optical switch and its associated sub-components are also studied. The eye-like resonator is also proposed for compact and continuously tunable delay line for multi-transmitter beamforming techniques so the signals reaching far field are aligned. In order to utilize the advantages of photonic signal processing, the fiber-waveguide interface based on Vertical Grating Coupler (VGC) is also studied. With the focus of reconfigurable optical switch and tunable delay line, this thesis demonstrates the concept of fab-less PIC industry and eventually lead to pervasive technology in the future