I’ve just been reading a little about photonics and was curious about something that is somewhat related.

Does powering a light emitting diode produce photons or are photons created by changing te state of existing energy?

JTQ said:

I’ve just been reading a little about photonics and was curious about something that is somewhat related.

JTQ said:

Does powering a light emitting diode produce photons

Yes.

JTQ said:

or are photons created by changing the state of existing energy?

Photons are “simply” quanta of electromagnetic energy. Energy can neither be created nor destroyed, just changed from one form to another (bearing in mind that rest mass is a form of energy).

Roughly speaking, an LED converts some of the potential energy of the electrons flowing through it into electromagnetic energy.

Wikipedia has an article with a cute diagram. I don’t know if that will answer your questions adequately, but I suppose it’s a reasonable starting point.