1. Two Source Interference

2. Wavefront splitting Interferometer

3. Young’s Double Slit Experiment

4. Young’s double slit

5. Path difference:

7. For a bright fringe,
For a dark fringe,
m: any integer

8. For two beams of equal irradiance (I0)

9. Visibility of the fringes (V)
Maximum and adjacent minimum of the fringe system

11. Thomas Young's Double Slit Experiment

12. Photograph of real fringe pattern for Young’s double slit

13. The two waves travel the same distance Therefore, they arrive in phase

14. The upper wave travels one wavelength farther
Therefore, the waves arrive in phase S' S

15. This is destructive interference
The upper wave travels one-half of a wavelength farther than the lower wave.
This is destructive interference S' S

16. Uses for Young’s Double Slit Experiment
Young’s Double Slit Experiment provides a
method for measuring wavelength of the light
This experiment gave the wave model of light a
great deal of credibility.

17. Fresnel double mirror P1 P2
© SPK

18. Fresnel biprism
© SPK

19. Lloyd’s mirror
© SPK

20. Billet’s split lens
© SPK

21. For a bright fringe, For a dark fringe,
Extra phase difference ±p in Lloyd’s mirror

22. Summary Wavefront splitting interferometers Young’s double slit
Fresnel double mirror
Fresnel double prism
Lloyd’s mirror

23. Reference
1. Optics
Author: Eugene Hecht
Class no. 535 HEC/O
Central library
IIT KGP