Wave Interference, a Light - double slit experiment.
interference is commonly encountered when two waves of the same wavelength are added together.
Wave Interference, as in Mathematics.
we see that if the two waves are in step (the technical term is 'in phase') they add together to produce a combined wave that has twice the amplitude.
if, on the other hand, they are exactly out of step (in 'antiphase') they cancel each other out.
result of waves interference with a phase difference & the same wavelength is a wave with a different phase & amplitude but with the same wavelength.
Wave Interference, with a Phase Difference.
the phase difference is δ = π/2 or 90 degrees.
the two waves interfere, with the resulting wave (blue) equal to the sum of these two waves.
Wave Interference, Water.
Source: , the Internet.