# Can various wavelengths participate in C/D Interference?

My question is can multiple wavelengths or at least two different wavelengths interfere with one another? I know that they usually have to be the 'same' wavelength, but you'd think they can vary a bit from one another, so what is the relationship of wavelength/frequency to interference?

This question popped up into my ol' mind grapes when reading this thread: Producing photons with same frequency, different amplitude wave

Basically I originally thought that the energy of an EM wave was simply put(I took general physics mind you but I don't mind you throwing on some math if that's what it takes) by the relationship to Planck's constant and the frequency, but when googling what amplitude specifically meant (I assumed it was the intensity of the wave, w/e that is) I learned that it is the sq.root of E. Therefore it seemed logical that Planck's constant, the frequency and the amplitude where all related, but that still eludes me as well. While David Z's answer from the above link clarified this situation for me, it left me wondering: he says that the energy described by the amplitude, compared to the energy described by Planck's constant and the frequency, can be related to each other through the quanta(i.e. 'photon' in simpler cases) in monochromatic light.

This got me thinking that if the location of a photon(or its crests/peaks) were important(as are its freq/wavelength), then can two waves of slightly different wavelengths influence each other?

Thanks for the help!

• Waves of all wavelengths interfere with each other. The interference patterns are simply modulated at the difference frequency of the two waves, which makes them harder to observe. This is true for classical as well as quantum fields. – CuriousOne Sep 5 '14 at 6:03