FierceWireless What the THF? Debate evolves over where terahertz starts Similarly, aligned with the device-related work, “we picked 10 THz as the end. So, 100 GHz to 10 THz. This definition was backed up by agencies within DoD, at the time the main ones investing on fundamental research in this area,” said Jornet, who is now an associate professor at Northeastern University.