Produce an EM wave through interference

[Sesse]

I am trying to understand why it is not possible to produce an EM wave through interference that is completely different from the source waves. For example why can't 2 or more EM waves outside the visible spectrum add up to produce light? I haven't had any physics since high school and I don't know where to look to find an answer for this. Any explanation is very much appreciated.

 

[ZapperZ]

Er... interference doesn't CHANGE the frequency of the light!

What would cause you to think that it can?

This also has nothing directly to do with quantum physics, and more of a classical wave question, which is where I'll move this to...

Zz.

 

[Bob_for_short]

I am trying to understand why it is not possible to produce an EM wave through interference that is completely different from the source waves. For example why can't 2 or more EM waves outside the visible spectrum add up to produce light? I haven't had any physics since high school and I don't know where to look to find an answer for this. Any explanation is very much appreciated.

It is not the interference that "mutiplies" photon frequency. There are anisotropical cristalls that permit to double or triple the initial laser frequency.

Also there are such phenomena as Stokes-Raman and anti-Stokes-Raman photon scattering from material that change the "reflected" frequency (increase and decrease both are possible). But these are one-photon processes - the frequency change is due to inealstic interaction with the matter, not beacuse of presence multiple photons in the incident beam.

You can find some information on all that in Wikipedia, I guess.

Bob.