New trends in terahertz electronics

Abstract

The rapid evolution of terahertz (THz) applications in imaging, material diagnostics, communication systems, etc. stimu- lates an intensive search for new solutions in design and fabrication of compact emitters and receivers. The particular place of THz range in the electromagnetic spectrum – between microwaves and the infrared one – defines the requirement to merge together different concepts in the development of devices for THz electronics needs. The present overview covers several new topics illustrating unprecedented possibilities of modern semiconductor nanotechnology to realize innovative compact devices for terahertz electronics. We describe operation principles of quantum cascade lasers (QCLs) giving special emphasis to the specifics of THz quantum cascade devices and obstacles in their development. As an illustration of successful confluence of different physical approaches, we report on semiconductor nanostructure-based THz sensors – nanometric field effect tran- sistors and asymmetric bow-tie diodes containing two-dimensional electron gas – which can successfully be employed for selective / broadband detection of the THz radiation.