1. Light as a wave - evidence

2. What are wave behaviors that are NOT particle behaviors? interference – constructive & destructive diffraction

3. Interference pattern from 2 sources. When 2 or more waves interact, they interfere both constructively and destructively.

5. Wavefronts in water

7. What is diffraction? https://www.youtube.com/watch?v=4E Dr2YY9lyA

8. Diffraction = bending around boundary.

9. Point to the water wave diffraction.

10. Diffraction around wall or pillar. What’s going on here? What is different?

11. Diffraction through slits. Curving is greater for opening that are nearer the.

12. Double Slit Demo

13. Interference Light rays will undergo superposition and interfere both constructively and destructively. Interference is a wave behavior!!

14. Young’s Double Slit Experiment If you pass coherent light rays through two slits, what will you see on a screen?

15. Used Coherent Monochromatic Light Source (laser)

17. Observed Pattern Demo here

18. The observed pattern results from a combination of diffraction & interference.

20. It’s like the circular ripples sent from 2 sources, now the 2 sources are the slits.

21. Nodal & Antinodal lines. Nodes occur when crests and troughs overlap – canceling each other. Waves are out of phase. Antinode lines occur when crest overlap with crests or troughs with troughs. Waves are in phase.

22. Node Antinode

23. Young’s Double Slit Experiment

25. Light shows diffraction, constructive and destructive interference. This is evidence light is a wave.

26. Polarization - Light as a transverse wave.

27. Only transverse waves can be polarized.

29. Polarization – forced to vibrate in only certain directions.

30. Light is part of EM spectrum defined by wavelength. All waves show all discussed behaviors except polarization. Only transverse waves can be polarized.

31. Summary Diffraction & Interference indicate light is a wave. Polarization indicates light is a transverse wave.

34. Fringe Pattern

35. Can measure of laser

36. = xd nL Relate distances to wavelength. = wavelength d = slit spacing n= order of fringe L = distance btw. Slits & screen

37. Example: A pair of slits are placed 13.7 m from a screen. A third order fringe is seen on the screen 2.5 cm from the central fringe. If the slits were cut 0.0960 cm apart, determine the wavelength of this light. Roughly what color is it? 584 nmyellow

39. The intensity drops off from the central maximum. It is apparent for sound & light.

45. Passing polarized light through another polarizer.

48. 40. OPTICS STREAMINGOPTICS STREAMING

50. Huygen’s Principle for Diffraction Wavelets that pass through the opening predict position of new fronts.