• Question: how do the lasers in your previous job/work function

    Asked by drbrains to Allan, Angela, Diva, Harriet, Nathan on 27 Jun 2012.
    • Photo: Allan Pang

      Allan Pang answered on 27 Jun 2012:

      I never really got to work with laser in my job.

      Probably the closest one I had work with is an X-ray beam. And basically, we use an X-ray beam to shoot protein crystals, which gives off a pattern that we can interpret using complex mathematics and create a model of the structure of a protein.

    • Photo: Nathan Langford

      Nathan Langford answered on 27 Jun 2012:

      Hi drbrains,

      Lasers are a special type of light source that can do really cool things. If you try to look at light coming from the sun, there are several things you can discover. Firstly, it’s made up of lots and lots of different colours. Secondly, if you look at different bits of the light, they are all kind of randomly put together. It’s like watching people in a crowded shopping centre – everyone walking in all different directions, out of step with each other and always getting in each other’s way.

      Now, a laser is different. A laser is light that’s built up in a special sort of way in what we call a “resonator”. If you’ve ever sung in your bathroom or yelled something in a concrete stairwell, you’ve probably heard how the resonance of the space turns your slightly scrambled sound into something much more pure. Well, that’s what happens inside a laser.

      The light that comes out of a laser is a very pure colour. It is all going in exactly the same direction in a narrow beam (we say it is “collimated”). And all the “bits” of light are locked in step with each other, so it’s like watching an army parade walk past – every soldier stepping on the ground at exactly the same time (we call this “coherent”).

      These three properties are what make lasers special.

      1) Because they’re very pure sources of light, in the sense that they only have one colour, we can choose specific lasers to target certain things, without hurting others. For example, you can remove tattoos by using a special frequency of light that is transmitted through the skin tissue and is only absorbed by the ink, which then gets broken up.

      2) Because they’re a very thin beam, you can use them to measure paths very carefully. For example, you can measure land accurately. You can make sure that the shape of a football pitch is perfect. And you can even send it to the moon and back and measure how far the moon is from the earth!

      3) Because it’s coherent, we can build lasers that are incredibly intense and can be focussed down to very small spot sizes. This makes lasers useful, for example, in surgery and also in industrial cutting. Did you know that your denim jeans were probably cut out using lasers?

    • Photo: Angela Lamb

      Angela Lamb answered on 27 Jun 2012:

      I don’t use lasers at the moment

    • Photo: Harriet Groom

      Harriet Groom answered on 28 Jun 2012:

      Hi drbrains – Nathan gave a really good answer so I won’t talk about how lazers work but I use them in my research in two ways:
      1. To detect whether cells have a certain protein or not
      2. To look at different proteins in cells under a microscope
      They are really useful and help me a lot in my work.

    • Photo: Diva Amon

      Diva Amon answered on 2 Jul 2012:

      Hey drbrains,

      I’m going to have to agree with Harriet. Nathan’s answer was awesome.
      In deep-sea biology, the only lasers we use are those fixed on the special robots or Remotely Operated Vehicles (ROVs) we use to dive deep down into the deep sea. We have two lasers mounted on the front of the robot exactly 10 cm apart. They shine their red laser dots out onto whatever we are seeing and because they are exactly 10 cm apart, we can use the two laser points as a gauge for the sizes of animals and other cool stuff we see in the deep sea. Simple and yet so efficient!

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