Hello All! My question is about the interference if the waves. For example, I have SEVERAL solutions of the wave equation in some area (several eigenvalues and corresponding eigenfunctions). I want to see if the would be an interference between these solutions. What should I do? I see the 2 ways: 1) use analytic sum of this functions. by this I mean to calculate the interference of the two plain waves of different amlitudes and wavelength. How can I do this? 2) sum directly two my solutions. BUT a question arises: can I suppose that the difference in phase between my two solutions of the wave equation is what I need? Can I state that the phase difference between the 2 eigenmodes of the equation is the real phase difference between these two field distributions?