N Slit Diffraction

  1. Single Slit Diffraction
  2. Single Slit Diffraction Examples
  3. N Slit Diffraction Pattern

Young's Double Slit Experiment and N-slit Diffraction Although the formulas inside this applet are correct for any values you input, the display is discretized and will not display the waves properly if you deviate too far from the default values (e.g. For choices which require resolutions less than the size of a pixel).

  1. A diffraction experiment in optics can require a lot of preparation but this simulation by Andrew Duffy offers not only a quick set up but also the ability to change the slit width instantly. Run the simulation and select “Single slit.” You can adjust the slit width and see the effect on the diffraction.
  2. Diffraction due to N-Slits (Grating): An arrangement consisting of large number of parallel slits of the same width and separated by equal opaque spaces is known as Diffraction grating.Gratings are constructed by ruling equidistant parallel lines on a transparent material such as glass, with a fine diamond point.
N Slit DiffractionN slit diffraction procedure
Single slit
Double slit
Three slits
Five slits
Diffraction and interference
Interference only

Under the Fraunhofer conditions, the light curve (intensity vs position) is obtained by multiplying the multiple slit interference expression times the single slit diffraction expression. The multiple slit arrangement is presumed to be constructed from a number of identical slits, each of which provides light distributed according to the single slit diffraction expression. The multiple slit interference typically involves smaller spatial dimensions, and therefore produces light and dark bands superimposed upon the single slit diffraction pattern.

Single Slit Diffraction


The progression to a larger number of slits shows a pattern of narrowing the high intensity peaks and a relative increase in their peak intensity. This progresses toward the diffraction grating, with a large number of extremely narrow slits. This gives very narrow and very high intensity peaks that are separated widely. Since the positions of the peaks depends upon the wavelength of the light, this gives high resolution in the separation of wavelengths. This makes the diffraction grating like a 'super prism'.

Single Slit Diffraction Examples

Single slit diffraction

N Slit Diffraction Pattern

Show intensity comparison