If the fields have components in the same direction, they constructively interfere, while opposite directions cause destructive interference.

Depending on the thickness of the film, different colours interfere constructively and destructively.

In a focal point, rays from a point light source meet again and may constructively or destructively interfere with each other.

Interferometry is the process of combining waves in such a way that they constructively interfere.

The resulting wave still has a visible period corresponding to the fundamental frequency because it is at this point that all higher harmonics constructively interfere.

The zones can be spaced so that the diffracted light constructively interferes at the desired focus, creating an image there.

Depending on the exact path length, these reflections can interfere destructively or constructively.

The volume varies like in a tremolo as the sounds alternately interfere constructively and destructively.

A physical interpretation is that when equals one, the two waves are in phase and they interfere constructively.

After recombination, the two beams interfere with each other constructively or destructively.