Why Does Intensity Diminish at the Ends in Young's Double Slit Experiment?

[sparsh]

Hi...
Could anyone please tell me that why does the intensity of the interference pattern get diminished towards the ends of the screen ?

And can anyone also tell me what is the theoretical number of maxima that can be obtained in YDS experiment for a given wavelength, and slit , screen separation ?

Thanks a lot
Sparsh

 

[Astronuc]

The beam of photons (or electrons) is generally toward the slits. In the case of light there is an assumption of planar waves at the slits. The light diffracts (scatters) through the slits. The greater the scattering angle the lower the intensity because scattering is preferred at lower angles. The scattering angle increases as one moves away from the beam line or axis formed by the light source and center of double slits.

Analysis of double and multiple slit interference.
http://hyperphysics.phy-astr.gsu.edu/Hbase/phyopt/slits.html#c1

 

[kyle8921]

Hello Sparsh,

The Young's Double Slit Experiment is a classic experiment that demonstrates the wave-like nature of light. When a beam of light is shone through two parallel slits, it diffracts and creates an interference pattern on a screen behind the slits. This pattern is caused by the constructive and destructive interference of the light waves passing through the two slits.

To answer your first question, the intensity of the interference pattern does indeed diminish towards the ends of the screen. This is because the light waves that pass through the outer edges of the slits have a longer path to travel to reach the screen compared to the waves passing through the center of the slits. This difference in path length causes a phase difference between the two waves, resulting in destructive interference at the edges and a decrease in intensity.

As for your second question, the theoretical number of maxima in the interference pattern can be calculated using the formula N = (wL)/d, where N is the number of maxima, w is the width of the slits, L is the distance between the slits and the screen, and d is the wavelength of the light. This formula assumes that the slits are very narrow and the screen is far away, so in reality, the number of maxima may be slightly different.

I hope this helps answer your questions. Keep exploring and learning about the fascinating world of light and its properties!