Posted by Lance on 05/03/06 20:29

Voinin said the following on 5/2/2006 17:31:

> So I see there are three factors here:
>
> 1) The responsiveness of the dye to laser light. Because the disc is
> moving faster at higher speeds and the specific location that the laser
> is writing to is moving faster, the laser doesn't have as much time to
> expose the dye and so the dye has to be more sensitive to the wavelength
> the laser is using. This begs the question: are faster discs more prone
> to decay by ambient light than discs rated for slower burn speeds?

I'm almost certain that the laser power gets boosted at higher speed. So
there's no requirement for a different dye for each speed rating.

Here's a laser power controller chip for doing laser power control:
http://www.semiconductors.philips.com/acrobat_download/literature/9397/75012273.pdf

Lance
*****

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