Question: How do you create lasers? And do they use radiation in them?

Joe Spencer answered on 10 Mar 2015:

Laser stands for Light Amplification by Stimulated Emission of Radiation (L.A.S.E.R)
So they emit radiation, but not like gamma rays or x-rays, all light is radiation, it ‘radiates’ outwards just like hear from a candle. Light comprises of various wavelengths, some of these are gamma-rays, some x-rays, some radio and microwaves, between them is visible radiation, red, green etc etc, the colours we see. So that’s what it means by radiation.

Now i’m a laser physicst so i’m going to try and keep this simple;
to make a laser you need some way of adding energy to a system (usually electricity, or even other lasers!)
you need a ‘gain medium’ – usually a crystal, this produces the light you want

2 mirrors – one with a tiny hole in it, and placed with the gain medium between the two so it looks like this:
( – ) bracket are mirrors, – is gain medium

You add some energy or a flash of light to this crystal which then emits more light, the light bounces off a mirror and onto another.This light bounces back and forth generating more and more of the same light, some of which doesn’t reflect off the mirror but goes through, making our laser beam.