3. The double slit

Here You will see an animation of a plane wave breaking through a double slit. 

Each of the two slits has a width, which is assumed little compared to the wavelength. As You already know from the animation of the single slit this means that from each of the two slits a ringwave will propagate.
It is the interference pattern arising from these two ringwaves You will observe.

Vary the physical parameters Yourself. One important parameter is the distance d  between the two slits.

Follow the propagation from start by
 clicking here.