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Diffraction

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

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Diffraction

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  1. Diffraction

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

  3. 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. 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.

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

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

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

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

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

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

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

  11. First Maximum 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.

  12. First Minimum • CD=/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.

  13. 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 ……

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

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

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

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

  18. Transmission grating Reflection grating

  19. For the 1st order Max 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 Max at:

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

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

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

  23. 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.

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

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

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

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

  28. Example 1

  29. Example 2

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

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

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