Question: what are lasers and how do you use them?

Joe Spencer answered on 10 Mar 2015:

Luna123,
Lasers are light in its purest Form.
When you see light from a bulb or the sun. It’s white, this means it’s made up of all the colours or wavelengths. If you’ve seen a rainbow each colour is part of what makes white light.
Lasers are special as they just single colours of one wavelength. You can make red light, blue, green. Any colour you want really. Even some colours you can’t see, like Infrared.

So a laser produces a highly focused beam of a single colour light at high power, just like a laser pen but mine are more powerful.
I use them in my lab and have to put the laser on a bench plug it into a water pump to keep it cool as they get hot. Then I have to direct the beam that comes out using lots of expensive mirrors and then I send it through essentially a magnifying glass to make a very small spot but really high intensity. Kind of like if you focus sunlight using a lens to burn leaves. I then look at the reflected light from the thing I’m interested in and see how this reflected light changes. This tells me stuff about the thing I’m looking at.
I’d love to go more in depth but will leave it at that for now. If you want to know more about lasers or what I do with them but ask 🙂
J