• Question: Are lasers always red?

    Asked by anawesomepersonlol to Claire, Kate, Matt, Rob, Sam on 24 Jun 2013.
    • Photo: Sam Geen

      Sam Geen answered on 24 Jun 2013:

      Nope! The colour of light comes from electrons jumping up and down energy levels in an atom. A laser is something that mainly causes electrons to jump through one energy level alone, which gives it a single colour. You can get green lasers, blue lasers, etc. Red light has less energy than blue light per light particle, or photon, so it needs the electrons to jump less in energy, but there’s no reason why you can’t make lasers any colour, or even infra-red or ultra-violet, if you can get the electrons to jump at that energy.

    • Photo: Claire Lee

      Claire Lee answered on 24 Jun 2013:

      Hi awesome!

      Nope, lasers aren’t always red, in fact they can come in all colours. A laser is really just a particular material that amplifies light of a given wavelength – send in a bit of light and you get a lot coming out.

      Different materials amplify different wavelengths, and it just happens that the simplest ones to make are the red ones, so they’re cheaper and readily available. (Also, since red has the least energy of all visible light, it does the least damage too).

      But there are other ones you can buy too – I have a green laser pointer, for example. Green light has more energy, so these are really nice for pointing at stars as the light goes much further! They are also more dangerous though,a nd you should never point one in somebody’s eye (any laser for that matter).

      Also, in some places you can go to jail if they catch you shining a green laser at an airplane or something, so you need to be really careful!

Comments