Postdoctoral Fellow, University of Ottawa
My research topic is focusing on using mature CMOS technology to develop various photonic devices.
As people increasingly use their mobile phones to watch streaming videos, listen to popular tracks and post stories in social networking, wireless data traffic has been experiencing a tremendous growth in the last twenty years. Also, with Internet of Things and visual reality emerging, current wireless communication networks bear a heavy burden of faster data rate and lower power consumption required by pervasive wireless-enable devices. To address this situation, new-generation wireless communication 5G is at its dawn. As a disruptive technology, photonics is expected to play a key role in 5G for the generation, transmission, processing and control of a high-frequency microwave signal. The key motivation of using photonics for microwave applications is large bandwidth and low loss offered by photonics. However, most of the microwave photonic systems proposed in the past are implemented based on discrete fiber-based optical components, which make the systems unsuitable for real applications due to the bulky size, expensive cost and high-power consumption. To have a compact size and seamlessly integration with the widely-used large-scale electronic integrated circuits, it is highly desirable that the microwave photonic systems could be implemented on a single silicon chip using well-developed CMOS technology. The key advantages when silicon photonic technology is applied to microwave photonic system implementations include a much smaller size, better stability, lower power consumption, and largely reduced packaging complexity. The overall cost would be significantly reduced with greatly improved overall system performance.
Specifically, my ongoing research is focused on using silicon photonic technology to develop various photonic devices and to realize the integration of microwave photonic system on a chip with enhanced performance and reduced power consumption. Achieving the main goal of my research will bring microwave photonics into the integration era, and enrich the silicon photonics functionalities. This is an important contribution, representing a significant achievement for both microwave photonics and silicon photonics. These technology combinations will also lead to revolutionary device applications in telecommunications, sensing and instrumentation
Abstract: A broadband optically tunable microwave phase shifter with a tunable phase shift covering the entire 360° range using three cascaded silicon-on-insulator (SOI) microring resonators (MRRs) that are optically pumped is proposed and experimentally demonstrated. The phase tuning is implemented based on the thermal nonlinear effect in the MRRs. By optically pumping the MRRs, the stored light in the MRRs is absorbed due to two photon absorption (TPA) to generate free carriers, which result in free carrier absorption (FCA). The FCA effect would lead to the heating of the MRRs and cause a redshift in the phase response, which is used to implement a microwave phase shifter with a tunable phase shift. The device is designated and fabricated on an SOI platform, which is experimentally evaluated. The experimental results show that by optically pumping the MRRs, a broadband microwave photonic phase shifter with a bandwidth of 7 GHz from 16 to 23 GHz with a tunable phase shift covering the entire 360° phase shift range is achieved.
Pub.: 11 Sep '15, Pinned: 08 Sep '17
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