Laser pointer?

Question

Should i get the 15mw 35mw or 55mw as my first strong laser pointer? i have handled lasers before and i dont want one that cant melt plastic with the cap add on. i also wanted to know does just looking at the point you are pointing to hurt your eyes or is it just when you point it in someone's eyes. what is the diff. between green and red lasers?

Answer 1

"just looking at the point you are pointing to hurt your eyes" Yes, if the surface is very reflective, and the reflection goes to your eyes.

green and red lasers? they put our green or red light.

Answer 2

Google "ANSI laser hazard class" for an explanation of the different hazard classes in terms of power levels.  A 55 mW CW laser, for example, is a class III laser, which means it is powerful enough to do retinal damage in under the time it takes you to blink.  (There is a technical term for this, "something aversion" I recall, the point is that if you shine it in your eye or someone else's eye, you can do a lot of damage.)  I know this may p**s you off, and I am not trying to be insulting, but although you may have handled lasers before, it doesn't sound like you know a lot about them.  A 55 mW laser is not a toy, and if you are going to buy something like that, it is a good idea to read up on the safety issues.  

A green laser is typically what is called a frequency doubled Nd:YAG.  What that means is the laser's primary wavelength is in the near-infrared, and they run that through a nonlinear crystal to double the frequency (halving the wavelength) to give you something in the green.  The canonical "green" Nd:YAG wavelength is 532 nm, but there are some variations on that as the newer solid state lasers don't use Nd:YAG primary oscillators, but some other variant where the Nd atoms are embedded in a different crystal than a YAG.  An orange laser will be a frequency-doubled laser whose primary oscillator runs at a little longer wavelength (i.e., farther into the infrared) than an Nd:YAG.  

Red lasers, in general, are laser-diodes and they are not frequency doubled.  The primary output of the laser is in the red.  That is why in general red pointers are cheaper than green or other colors, there is less optics inside them.