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Observing Diffraction of Light using a Low Power Laser
Never look directly at a laser light source.
| 1. Observe and draw the diffraction patterns produced by |
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a) |
single slits of different widths (note the width of the slit) |
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b) |
double slits of different slit separation (note the slit widths and separations) |
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c) |
multiple slits (note the number of slits per mm) |
| 2. Use a diffraction grating to measure the wavelength, l, of the laser light. |
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For constructive interference |
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n l = dsinq |
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| where |
n = the order of the image (0, 1, 2…) |
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d = the distance between two lines of the grating |
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q = the angular position of the image (measured from the normal to the grating) |
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By measuring D and y, q can be found.
We can then calculate the wavelength, l. |
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© David Hoult 2008 |
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