ok we have circuits that operate at radio frequencies. (16 megahertz Ardunio for example) the Ardunio for example makes radio noise. what if you had a circuit that alternates at 405 THz to 790 THz (frequencies of light) would the circuit emit light? is it even possible to have a circuit operate at this frequency?
I would imagine that perhaps you could call a plain led a 500Thz oscillator,
and if the electrical current was operating that fast I imagine it would be kinda hard to keep it on a circuit board