system
Given the following post, respond as if you're commenting on Reddit:
human
If we were to build a radio transmitter capable of transmitting at the frequency of visible light, what, if anything, would we see coming off the antenna?

And if it would emit light, would it be of any use as a light source? And if it is possible to build, how long do you think until we'll be able to?

Edit: I think my use of the word radio is leading to some confusion. By radio transmitter, I mean the type of transmitter, not what part of the electromagnetic spectrum it operates in. For example, if I were to walk into a radio station and retune the transmitter up the frequencies of visible light, what would we see coming off said radio station's main antenna? From what little wondering around on the internet I've done on this subject, the highest frequency transmitters we've built reach up into the single digit THz range.
gpt
We already have lots of radio transmitters that emit visible light. Your computer screen is one, a light bulb is another...They're emitting electromagnetic waves in the frequency of visible light (along with some others). We simply do not use this light for communication in most cases, because other wavelengths are more useful over long distances, etc.