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Q & A: Building a laser

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Most recent answer: 10/22/2007
Q:
I would like to make a laser light for my science class project. Could you tell me if it is possible and how would I go about getting. I was wondering if there are kits that tell walk you though the process? Thank you
- Jordan
Rolling Bay Elementary, Wa. USA
A:
Jordan,

Building a laser sounds like a lot of fun, but it is not easy!
There are several ways you can build a laser. Probably the easiest way is to purchase a Helium Neon Laser tube and connect it to a ready made power supply. This will make a red light that you can see, but does not involve a lot of construction time or skill. The parts for something like this will probably cost somewhere around $50-$75. Some resources I found for these parts are:



, and here is a link directly to their . You will need adobe acrobat reader to view their catalog.

If you are a little bit more ambitious, and have more money you can try a Nitrogen laser, a carbon dioxide laser, or a YAG (yttrium-aluminum-garnet) laser. A particularly good page with information about these is located below.



If these end up being too difficult or expensive, I'd suggest trying, instead, to get an already working laser and find some fun projects to DO with it. You can easily go to Walgreens or Radio Shack and buy a laser pointer for under $15. These contain small laser diodes which produce a beam that is suitable for making holograms, or generally experimenting with light. Some things I thought of to try are:

Attach a mirror onto a speaker (right on the paper cone) and point the laser right at the mirror. It will bounce off of the mirror and hit the wall somewhere. Play some music through the speaker and watch what happens to the spot.

Explore the differences between a laser and a flash light. Try pointing them at things that are far away and close-up. Try pointing the laser through some different lenses, maybe through a prism and see what happens.

Cut a hole in one end of a shoebox, Take a piece of your hair and stretch it across the hole and glue or tape it so it is straight. Now shine the laser on the hair and see what the light looks like on the other side of the box. You shouldn't see just a shadow of the hair (this is called diffraction). If your laser pointer is oval or square you may need to turn the laser so the longer direction of the laser spot and the hair are going the same direction. It may also help to put a piece of white paper at the end of the box as a flat screen.

Good luck!

-matthew

(published on 10/22/2007)

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