2. http://www.launc.tased.edu.au/online/sciences/physics/diffrac.html

6. What is the difference between interference & diffraction? Interference involves the superposition of waves of (the same / two different) wave fronts, in diffraction there is a superposition of waves from (the same part / different part )of the same wave front.

7. http://micro.magnet.fsu.edu/primer/lightandcolor/diffractionintro.html Diffraction of Light

8. http://www.falstad.com/diffraction/index.html Aperture: Slit, circular and square

9. http://www.falstad.com/diffraction/ind ex.html Aperture: Slit, circular and square

10. http://micro.magnet.fsu.edu/primer/java/diffraction/particlesize/index.html

11. http://micro.magnet.fsu.edu/primer/java/diffraction/basicdiffraction/index.html Diffraction of Light

12. http://hyperphysics.phy-astr.gsu.edu/hbase/phyopt/diffracon.html

16. Normal incidence The secondary sources on the wavefront between the edges of the barrier sending waves arriving at the central point are in phase. Central Maximum

17. First maximum The slit is divided into 3 equal parts and the wavelets from the strips in two adjacent parts cancel, leaving only wavelets from one part to give a much less bright band. First Maximum

18. 2CD= /2 or BE= At a particular direction , CD= /2 or BE=. A and C and C and B are out of phase. The points just below A and points just below C are also out of phase. Consecutively, pairs of points are out of phase also. It gives destructive interference. First Minimum

19. Hence By similar pairing process, other minima occur when, where n =  1,  2,  3….. The maxima occur roughly half-way between the minima at angles such that sin  =  3 /2a,  5 /2a ……

23. http://hyperphysics.phy-astr.gsu.edu/hbase/phyopt/grating.html#c1 Diffraction Grating

24. http://hyperphysics.phy-astr.gsu.edu/hbase/phyopt/gratcal.html

25. Line Spacing Calculations from Diffraction Gratings http://micro.magnet.fsu.edu/primer/java/diffraction/diffractionorders/index.html

26. http://www.ppo.ca/gratings.htm

27. Transmission grating Reflection grating

28. What is the path difference between the 1st slit and 2nd slit? What is the path difference between the 1st slit and 3rd slit? 2 For the 1st order Max Max at:

29. Angular width of the first maximum Angular position Intensity  ’’ Angular width = 2(  ’ -  )

30. Angular width of the first maximum Max at: Min at: Pairwise cancellation : 1-5, 2-6, 3-7, 4-8 Consider 8 slits, for example (1) (2) (3) (4) (5) (6) (7) (8)

31. Angular width of the first maximum Angular position Intensity  ’’ Angular width = 2(  ’ -  )

32. d = a + b grating   Explanation of the grating equation The path difference between the wavelets is d sin , as it is for all pairs of wavelets from other corresponding points in these 2 slits and in all pairs of slits in the grating.

33. http://micro.magnet.fsu.edu/primer/java/imageformation/gratingdiffraction/index.html

34. http://lectureonline.cl.msu.edu/~mmp/kap27/Gary-Diffraction/app.htm

35. http://www.phys.hawaii.edu/~teb/optics/java/slitdiffr/

38. http://www.schulphysik.de/suren/Applets.html

39. Example 1

43. Example 2

49. Diffraction of electrons …… http://phys.educ.ksu.edu/vqm/html/doubleslit/

50. http://micro.magnet.fsu.edu/primer/java/imageformation/airydiskbasics/index.html

59. http://micro.magnet.fsu.edu/search/index.asp END