Frequency of your CD writer's laser

Hi. Just curious about the workings of the laser in your drive. Does:

  1. The frequency of the laser change when you go from CD-R(write) to CD-RW(write) to CD-R/RW(read)?
  2. Does the power of the laser change when you go from CD-R(write) to CD-RW(write) to CD-R/RW(read)?
  3. Do different drives with different read/write speeds use lasers of different frequency/power, or do they just have faster processors to process the signals from the receive/write parts?
  4. What is the typical frequency for the laser?

Since one possible colour for the written surface of a CD-R is black, this leads me to suggest that the frequency of the laser must be in the infra-red range. An ultraviolet laser, IMO, would be able to both resolve and write much finer pits, because of its shorter wavelength.

  1. AFAIK no
  2. yes
  3. different power only
  4. IIRC 650nm for DVD-R(G)/RW, 635nm for DVD-R(A), and afaik about 780nm for CDs

Also see the Blu-Ray article :bigsmile: