Universal terahertz integrated systems: Bridging the 'THz' and 'Application' gap in the next decade

The spectrum beyond 100 GHz has undergone transformative changes in the past decade, both in the form of technological progress and simultaneously in application development. With the evolution of 5G in the sister millimeter-wave band, the field of integrated THz technology has progressed significantly towards enabling efficient and compact Terahertz systems operable at room temperature and deployable at large scales. This has been facilitated by key developments in a multitude of integrated technology substrates in electronics, photonics and also hybrid systems. While f_max of III-V based devices have crossed 1.5 THz, silicon-based THz systems have shown remarkable advancements in complex systems including chip-scale phased arrays, active and passive imagers, and wireless communication systems. While this technological progress has led to steady closing of the 'THz gap' in the past ten years, there needs to be concerted effort in closing the 'THz' and 'application' gap in the next ten years to allow large scale deployment of THz technology. In this paper, we summarize the advancements in integrated THz systems in the past decade, discuss future challenges and directions to progress towards that goal.