Lakhasly

An explanation for diffraction phenomena occurring from double slits is possible if wave properties are assigned to the light and if the slits are considered to be two coherent light sources whose light bundles superimpose.For light bundles that emerge under the angle @ this is true each time when the path difference & between the principal rays is an integer multiple of the wavelength 2 of the light:

An explanation for diffraction phenomena occurring from double slits is possible if wave properties are assigned to the light and if the slits are considered to be two coherent light sources whose light bundles superimpose. The superposition leads to destructive and constructive interference in certain directions. In a simple approach, the light bundles coming from the slits are first subdivided into (infinitely) many partial bundles. Then it can be made clear with the aid of Fig. 2 that maximum intensity occurs in directions in which there is exactly one partial bundle from the second slit which corresponds to any partial bundle from the first slit so that both interfere constructively. For light bundles that emerge under the angle @ this is true each time when the path difference & between the principal rays is an integer multiple of the wavelength 2 of the light: