Intellectual Merit: The objective of this proposal is to develop terahertz interconnect compatible and scalable with silicon processes to address the long-standing interconnect issue. The ever-increasing inter- and intra- chip communication bandwidth imposes a big challenge over decades: interconnect bottleneck. Existing electronic interconnect (EI) and optic interconnect (OI) cannot address the interconnect issue by their own. These result in the "last centimeter" dilemma in data links. THz unique spectrum, sitting between microwave and optic frequencies, allows it to enjoy advantages of both low cost, high reliability electronic processing and low loss, small size transmission channels, therefore holds great promises in interconnect area to bridge the "last centimeter" link. Ultimate interconnect solutions mandate high energy efficiency, high bandwidth density, high reliability, low cost, as well as a fast adaptability and scaling capability with process advancements. To address this multi-dimension challenge, the PI proposes THz Interconnect research, including the investigation of TI theory, channel design, circuit implementation techniques and demonstration validation. Particularly, we will investigate three crucial enabling techniques: planar silicon process compatible channels and couplers, the high efficiency self-oscillating harmonic power amplifier based transmitter, and the high sensitivity receiver. THz interconnect system architecture and fundamental performance limits given practical circuit/system constraints, and TI scalability with process advancements will also be investigated. To the PI's knowledge, this will be the first time to investigate THz Interconnect compatible with mainstream silicon technologies. THz interconnect theory discovers the understanding of the bandwidth density and energy efficiency limits of the interconnect, and leads to evolving TI architectures that scale performance with technologies to ultimately close the interconnect gap. If successful, THz Interconnect will provide orders of magnitude better bandwidth density and energy efficiency than existing interconnects to ultimately address the last centimeter interconnect issue. Broader Impacts: THz interconnect development opens a new, high potential application for the under-utilized THz spectrum. The PI also envisions that the success of THz interconnect will enable new computer architectures to satisfy the ever-increasing bandwidth requirement in the BIG DATA era. It will also save tremendous energy to not only bring significant economic impacts, but also mitigate global warming problems. THz interconnect will form a killer application for the under-utilized THz spectrum to further motivate THz advancements and impact our lives and societies in larger and deeper scales. The PI will also integrate research with education and outreach programs, and broadly disseminate the research results through publications.
