This research harnesses photonics to satisfy ever-growing government, industry, and consumer needs for data bandwidth, while significantly reducing the increasingly voracious energy footprint that accompanies Internet cloud use. Photonics uses light instead of electronics to perform a variety of functions such as information processing and transfer. While most of us still work in offices and meet friends in person, mobile and networking device capability has enabled massive online business and social transaction growth. The Internet and its cloud-based services are used for production systems, banking, entertainment, social interaction, information distribution and research. Resulting information accumulation is fueling the rise of "big data," as well as the powerful correlation tools that help analysts spot financial trends, prevent diseases, combat crime and improve quality of research. More and more, we put content in the cloud for easy access from anywhere and at any time, with data growing exponentially. All this data transfer uses a surprising amount of energy. To reduce data center energy consumption while increasing data capacity by over ten fold, this research will investigate novel hybrid data communication interfaces, using light rather than electrons to process and transfer data at higher speeds. The potentially explosive increase in data rates enabled by these hybrid photonic interconnects could lead to several transformative applications, such as future exascale data centers, terabit speed local area networks, and massively-parallel computing for big data applications. These hybrid photonic interconnects will not only have a broad impact on the semiconductor industry, but also US energy sustainability and security, as more energy-efficient computing systems would reduce carbon footprint of the Internet cloud. Further, to prepare students for the workforce with the necessary skills to drive future technology, the project includes a strong educational component. Interactive learning methods will be employed to teach electronic circuits and to bring photonics to integrated circuit design. The project also incorporates a high school outreach program, with an annual Smart Environments for Sustainability-themed one-week summer camp for high school students that commits to fostering women and minority group representation in integrated circuit design.
Technology development leveraging integrated photonic circuits and optical interconnects has thus far largely focused on binary communication using silicon photonic modulators. To enable future optical interconnects for higher data rates and energy-efficiency, researchers must reconsider the hybrid integrated circuit paradigm. An important technology enabler is the high-speed signal processing capability of integrated photonic devices. The research approach will first be to develop a photonic design kit with standard cell libraries and compact models to enable large scale integration of photonic devices into hybrid integrated circuits. Researchers will employ photonic device high-speed optical domain signal processing into novel circuit configurations, exploit synergistic interaction between electronic and photonic components, and form a mixed-signal photonic architecture. Next, to exploit photonics beyond binary interconnects; researchers will develop novel mixed-signal photonic data converters, which they will use to demonstrate an advanced modulation transceiver architecture that is scalable to terabits per second data rates with order-of-magnitude lower energy consumption. Research outcomes will empower integrated circuit researchers by equipping them with a new photonics expertise to tackle nano-scaled technology design challenges, where data transfer bottlenecks constrain system performance. The photonic design kit will lower industry barriers to help facilitate photonics adoption into integrated circuits; resulting mixed-signal photonic data converter architectures will set a new paradigm by achieving greater than 10 GHz sampling rates with significantly reduced energy consumption over existing complementary metal?oxide?semiconductor (CMOS)-only architectures. Researchers will broadly disseminate project results by developing online educational material for a new CMOS photonics integrated circuit design graduate course, and through international journals and conferences.
