Optical and Terahertz Wireless Technologies: the Race to 6G Communications

Terahertz and optical wireless communications (OWC) technologies have been considered as promising enablers that have potential to contribute equally to the realization of a sixth-generation (6G) wireless future. Experimental demonstrations show that, although inherently different, both technology types can support multi-kilometer Tbit/s wireless data transmission, which is a key goal set by almost all 6G roadmaps. Although both technology types can contribute equally to the realization of 6G roadmaps, to date, the development of these technologies for communications and non-communications applications has been ongoing independently. This is mainly because the distant similarity between both technology types masks their competitive performance. This article complements efforts made by academia and industry to explore the potentials and challenges of terahertz and OWC technologies as key enablers for 6G applications. Specifically, we weigh up the pros and cons of both technology types based on selected key metrics. The purpose of these comparisons is to highlight application areas in which strengths of these technologies could potentially be integrated.