# Physics 6805: Diffraction 101

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## Recent changes to this page:

• 21-Aug-2017 --- Revised 2017 version from LaTeX version.

## Slides

### Diffraction 101 (review?)

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### Intensity as a Function of Angle

Single-slit diffraction: first minimum when sin θmin = λ/a ⇒ pattern widens as λ increases.

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### Diffraction from a circular hole

The diffraction pattern of a circular hole of diameter d is similar to that of a single slit of width a. The bright spot in the middle is the Airy disk. It has about 85% of the power in the pattern. Minima are at:
sin θ1 = 1.22 λ/d
sin θ1 = 2.23 λ/d
sin θ1 = 3.24 λ/d

What is the diffraction pattern from a solid disk? (Hint: Babinet)

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### Diffraction and resolution

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### Wavelength and resolution

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### Consequences

For a slit of width a, θmin = sin-1(λ/a), so if λ>a, you don't learn anything about the details of the slit.

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### Quantum Mechanics and Resolving Power

The de Broglie relation is λ = h/p.
For λ≈10-10m ⇒ probe atoms
For λ≈10-14m ⇒ probe nucleus
For λ≈10-18m ⇒ probe quarks

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Your comments and suggestions are appreciated.
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Physics 6805 .
Last modified: 02:12 pm, August 21, 2017.
furnstahl.1@osu.edu