One problem with common CD-ROM media is that excessive exposure to heat or infrared radiation may cause the dyes in them to change, thus causing bit rot. My idea would be to use a multi-chemical emulsion which would be written with using high-power infra red laser, but could then be "fixed" via generous exposure to ultraviolet light.
A suggested implementation would be to have a pair of chemicals that reacts when heated or exposed to strong infra-red radiation, but have one of the chemicals react so as to become inert when exposed to ultra violet. Thus, the places where the chemicals had reacted in response to infra-red before the ultraviolet 'fixing' step would remain reacted, but those places where they had not would no longer be sensitive to heat.-- supercat, Mar 05 2008 Well, someone liked the idea. Anyone have any comments, or any idea of the feasibility?-- supercat, Mar 05 2008 Notg my bun, but sounds like it ought to be doable.-- MaxwellBuchanan, Mar 06 2008 I’m intrigued by this, and wonder if some combination of chemicals could prove to be more durable than current metallized discs. Maybe so. I am familiar with photographic processes for masking (sandblasting glass, and silkscreening), but the unexposed parts of the mask must be processed further (rinsed away) to reveal the areas that have set. Otherwise, it's identical to an undeveloped sheet.
You must keep the discs protected from light until the entire process is complete. Unless the drive holds a spindle in the dark, the CD-ROM blanks must be individually packaged. Human eyes can’t detect ultra-violet or infra-red, so if a disc is damaged by radiation from any source, you don’t know until you’re done and try to read it. Try to write to an ordinary CD-ROM that has flaws, and you know during the write process. It’s not a criticism, just an observation that these will require special handling. I can’t just keep my blank CD-ROMS strewn out on the lawn anymore.
What happens to the chemicals as they react to the radiation to make the drive able to read the data? Is there a color contrast or reflectivity change?-- Amos Kito, Mar 06 2008 random, halfbakery