Describe the young's double slit experiment …

Young’s double slit experiment (YDSE)

The Young’s experiment shows that matter and energy can display both wave and particle characteristics.

Purpose of double slit experiment is as follows:-

1. In order to prove the wave nature of light.
2. To explain the phenomenon of interference.

Two coherent sources of light were taken in order to maintain the 0 or constant phase difference between the sources of light.

• Experimental set-up1:-
  • Young took an ordinary source of light(S) such as light bulb.
  • The light was made to pass through a very small slit S (which was comparable with the wavelength of light).
  • The light coming from Source S was made to pass through two small slits S1 and S2 which were separated by a very small distance d.
  • One screen was kept in front of these 2 sources.

Observation1:-

• He observed alternate dark and light bands were formed on the screen.

Setup 2:-

• Now he took 2 light bulbs i.e. 2 non coherent sources of light and placed a screen in front of them.

Observation 2:-

• He observed there were no alternate bands of light formed on the screen.
• Conclusion:-
• When coherent sources of light were taken then the phenomenon of interference is taking place.
• When non-coherent sources were taken phenomenon of interference was not taking place.