Re: How to make laser ray device for optics demo?

Robert wrote:
Next month I am going to be teaching a class about optics, and I'd like to use a set of lasers to show them how rays diverge and converge in various situations. Students will literally be able to see things like this:
http://www.colorado.edu/physics/phys...1/topic23.html

Frey Scientific sells what looks to be a wonderful device: It has 5 side-by-side, 1 mW diode lasers, all lined up next to each other. It makes five parallel lines that do not diverge (at least not to a significant degree over the length of a lab table!)

These are great to aim at lenses or mirrors for ray tracing, optics experiments, etc. The only problem is that each device costs $380, which is total garbage. These low power laser diodes only cost them $10 each at most, probably less.

Laser Ray Box Item #: 1552737821
https://www.schoolspecialtyonline.ne...CC88941A1 F8B

It occurs to me that I should be able to build a useful device with cheaper, lower power, pointer lasers. These can be purchased for $5 to $20 each. But the trick is finding cheap lasers with a useful on/off switch. All the cheap lasers I see have no real switch. You have to constantly put your thumb down on the switch to turn it on, and the moment you let go it turns off. Not convenient. Do you know of any affordable, small lasers, that can be turned on - and stay on until they are switched off?

I've never done this before, but I am thinking of picking up cheap laser diodes, and soldering them together to a battery, or some power source, but I don't quite know how to do this. Its supposed to be easy, but not having done this before, I need some sort of instruction. Any idea on where I might find good instructions, including photos?

Take a look at these cheap laser components: I was thinking of picking some up here, but I am open to any suggestions!

http://www.wholesaleforeveryone.com/...o de=lasermod

Thanks much for your time,

Robert


1) Good idea. You should be able to pick up cheap laser pointers for <$5

2) You need to improve your URL copy & paste skills! Not one of your links worked directly...

3) At the last site, WholeSaleForEveryone.com try their part number EXLM515 for $7. Wire all the laser diodes in parallel, with one switch, to two 'D' cells in series, for 3V. Should run for many hours.

Dave
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