• Question: How do lasers create DVDs and CDs?

    Asked by kentf002 to Mike, Pip, Tianfu, Tim, Tom on 29 Jun 2012.
    • Photo: Tim Stephens

      Tim Stephens answered on 29 Jun 2012:

      The information on a CD or DVD is written on the surface as a pattern of dots. As the CD is read, a laser is reflected (or not reflected, depending on the pattern) and the player can understand the pattern and read the data or play the music.
      To write to the CD you use a more powerful laser, or turn up the power on the one that you have, and literally burn the dots onto the surface.

    • Photo: Tom Lister

      Tom Lister answered on 29 Jun 2012:

      Good answer. It’s a bit like a really tiny bar code then? Or one of those newfangled QR codes?

Comments