How do DVD +/- Recordable disks work?

[raid517]

Hi I am doing a project at college and I need to do a report on how DVD-Rs work. I have heard that there are soon to be new 8GB dual layer DVD-Rs and I am very interested in how this 'double layering' works?

I mean, when we talk about burning a DVD, is that really what happens? Is the process of writing to a DVD a thermal process? And if so and if these DVDs really are dual layered, what prevents the heat used to burn one layer from bleeding into the other and affecting it?

How chemically is it possible to change the properties of varius multilayered surfaces using heat, without the heat source you are using affecting any of the subsquent (and similarly constituded) layers? (I need to figure this out in order to demonstrate a more general principal).

I did search Google - and unfortunately many of the examples I found were either way too technical for the broad audience it is aimed at, or it was not technical enough - in that it provided very little information that would help those who at least had some basic knowledge of the subject, to improve their understanding.

Something like a science journal article aimed at skilled lay people would be a good starting point. Or maybe some of you guys can supply your own input?

Any input anyone can offer would be very much appreciated.

Kind regards,

GJ

[b1tchm4gn3t]

go to howstuffworks.com or something like that...I learned a bunch from there

[cdb]

A few weeks ago someone posted this link, which is now a sticky topic in the "Media" forum. It's a 12 minute video which explains how commercial "pressed" and DVD+/-R "burned" discs are created, and how the DVD drive reads them. It's an excellent reference. Won't answer *all* your questions but will cover a lot of them

http://www.upgradingandrepairingpcs.com/videos/15th/high/7_Optical_Drives.wmv