> except typically with frequency range in microwaves instead of visible light

That's a big freaking deal.

eg, consider WiFi. They choose their bands carefully for wireless standards, and terahertz is pretty far from microwave GHz. I've never seen direct THz synthesis outside of partially-insane radar engineers.

I thought half the controversial scanners since 9/11 were THz (the other half being backscatter X-ray)? Was that just a marketing term?

(I can easily imagine "terahertz for terrorism" being a slogan…)