Diffraction (6.161 Lab3) Tony Hyun Kim 10/21/2008.
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Transcript of Diffraction (6.161 Lab3) Tony Hyun Kim 10/21/2008.
![Page 1: Diffraction (6.161 Lab3) Tony Hyun Kim 10/21/2008.](https://reader035.fdocuments.us/reader035/viewer/2022062317/5a4d1b447f8b9ab0599a2cde/html5/thumbnails/1.jpg)
Diffraction (6.161 Lab3)Tony Hyun Kim
10/21/2008
![Page 2: Diffraction (6.161 Lab3) Tony Hyun Kim 10/21/2008.](https://reader035.fdocuments.us/reader035/viewer/2022062317/5a4d1b447f8b9ab0599a2cde/html5/thumbnails/2.jpg)
Topics to be discussed
1. Introduction1. Diffraction theory2. Fraunhofer diffraction integral
2. Experimental setup3. Patterns from apertures
1. Single-slit2. Double-slit3. Rectangular aperture4. Rectangular grid
4. Conclusions
![Page 3: Diffraction (6.161 Lab3) Tony Hyun Kim 10/21/2008.](https://reader035.fdocuments.us/reader035/viewer/2022062317/5a4d1b447f8b9ab0599a2cde/html5/thumbnails/3.jpg)
Diffraction = Wave - Ray
Although ray optics is intuitive…
Light is a wave phenomenon
![Page 4: Diffraction (6.161 Lab3) Tony Hyun Kim 10/21/2008.](https://reader035.fdocuments.us/reader035/viewer/2022062317/5a4d1b447f8b9ab0599a2cde/html5/thumbnails/4.jpg)
Fraunhofer diffraction integral
'
)''(2)(2
'')','('),(
22
dydxeyxuzi
eeyxUyyxx
zi
yxzik
ikz
'
![Page 5: Diffraction (6.161 Lab3) Tony Hyun Kim 10/21/2008.](https://reader035.fdocuments.us/reader035/viewer/2022062317/5a4d1b447f8b9ab0599a2cde/html5/thumbnails/5.jpg)
Fraunhofer intensity pattern
22 ))','('(),( yxuFyxUI
'
![Page 6: Diffraction (6.161 Lab3) Tony Hyun Kim 10/21/2008.](https://reader035.fdocuments.us/reader035/viewer/2022062317/5a4d1b447f8b9ab0599a2cde/html5/thumbnails/6.jpg)
Setup to observe diffraction
![Page 7: Diffraction (6.161 Lab3) Tony Hyun Kim 10/21/2008.](https://reader035.fdocuments.us/reader035/viewer/2022062317/5a4d1b447f8b9ab0599a2cde/html5/thumbnails/7.jpg)
Patterns from apertures
We’ll present and analyze (Topic set 1):
1. Single-slit2. Double-slit3. Rectangular aperture4. Rectangular grid
![Page 8: Diffraction (6.161 Lab3) Tony Hyun Kim 10/21/2008.](https://reader035.fdocuments.us/reader035/viewer/2022062317/5a4d1b447f8b9ab0599a2cde/html5/thumbnails/8.jpg)
Single slit
b
bz2
Note Fourier reciprocity in characteristic lengths Calculate slit width from pattern: b = 89
microns
![Page 9: Diffraction (6.161 Lab3) Tony Hyun Kim 10/21/2008.](https://reader035.fdocuments.us/reader035/viewer/2022062317/5a4d1b447f8b9ab0599a2cde/html5/thumbnails/9.jpg)
Double slit
Periodicity in aperture produces localization in
pattern Calculate inter-slit distance: D = 6.5 mm
D
Dz2
![Page 10: Diffraction (6.161 Lab3) Tony Hyun Kim 10/21/2008.](https://reader035.fdocuments.us/reader035/viewer/2022062317/5a4d1b447f8b9ab0599a2cde/html5/thumbnails/10.jpg)
Rectangular aperture
Just a slit in two dimensions Calculate aperture dimensions: b = 76 microns
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Rectangular grid
Again, periodicity localization
![Page 12: Diffraction (6.161 Lab3) Tony Hyun Kim 10/21/2008.](https://reader035.fdocuments.us/reader035/viewer/2022062317/5a4d1b447f8b9ab0599a2cde/html5/thumbnails/12.jpg)
Concluding remarks
Verified Fraunhofer diffraction in lab
General lessons: “Fourier pairing” between aperture and
pattern Reciprocity in characteristic lengths. Periodicity of aperture Localization of
pattern
Possibilities for metrology
![Page 13: Diffraction (6.161 Lab3) Tony Hyun Kim 10/21/2008.](https://reader035.fdocuments.us/reader035/viewer/2022062317/5a4d1b447f8b9ab0599a2cde/html5/thumbnails/13.jpg)
Sources of images Lens system:
http://www.trustedreviews.com/images/article/inline/4778-ZoomOut500.gif Fraunhofer planes:
http://scienceworld.wolfram.com/physics/FraunhoferDiffraction.html Experimental setup: 6.161 Lab guide