6a10.15.HTML
6a10.15: VISIBLE LASER

PURPOSE: To show what the inside of a laser looks like, and to show that the laser removes lots of spectral components from the light in the tube and only lets one wavelength out.

DESCRIPTION: The metal cover has been removed from a weak helium-neon laser, allowing the internal components to be seen, including the tube and the mirrors. Using a hand-held diffraction grating the light from in the tube can be seen to have a large number of spectral components. The light outside hits a white screen; looking at the spot with the grating shows that it is monochromatic, illustrating the lasing action.

SUGGESTIONS: This one is best for individual viewing by a few people at a time.

REFERENCES:

EQUIPMENT: Laser with case removed mounted in clear plastic tube, white card, diffraction gratings.

SETUP TIME: None.


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