Heterogeneous Photonic Integrated Circuits for Microwave Photonics

点击翻译按钮获取中文摘要

Microwave photonics (MWP) is an interdisciplinary field to study the generation, processing, control and distribution of microwave signals by means of photonics, which can find applications such as broadband wireless communications, radar, high-speed sensing, high-resolution imaging, and modern instrumentation. Various MWP systems have been proposed and demonstrated in the past few years. These systems, however, were implemented based on discrete photonic components, which makes the systems bulky, heavy and costly with relatively poor performance. To overcome these limitations, there is an ever-increasing interest in using photonic integrated circuits (PICs) to realize on-chip integration of MWP systems. Currently, there are three major material systems that are being studied for integrated MWP implementations: 1) Indium Phosphide (InP), 2) Silicon Nitride (Si3N4) and 3) Silicon photonics (Si). Si-based PICs using the standard and well-developed CMOS fabrication process to develop and manufacture optical devices on silicon-on-insulator (SOI) platforms has been considered a potential solution for integrated microwave photonic systems. The key advantages include much smaller footprint, low power consumption and compatible fabrication process with CMOS technology, which also holds a significant potential for seamless integration with microelectronics. However, one key factor limiting the Si for monolithic integration is the lack of light sources and amplifiers, since silicon is a non-direct bandgap material. A potential solution is to integrate InP-based light sources and amplifiers on a silicon chip through heterogeneous integration. This approach combines the benefits of two different material systems to provide a unique solution to light generation and amplification. The motivation of the proposed research is to study the use of the heterogeneous integration technology to develop fully integrated MWP systems for the generation and processing of high-frequency and frequency-tunable microwave signals. The combination of the InP-based and Si-based PICs would significantly boost the performance of microwave photonic systems and opens up new avenues toward real applications.