The Optical Drive

By Michaela Holmes

How does it work?

The optical drive is more commonly called the DVD burner or DVD drive, but the technical term for these drives is "optical drive." This is because that's how they work, and all of them are variations on a main idea: a motor spins the disc in the drive very fast while a laser attached to a servo reads data off of it. These drives tend to be loud and draw a lot of power since a lot of stuff is moving.

Anatomy of a disc

You need to understand optical dics before looking at optical drives. The disc is pretty much three layers: the big plastic disc part is on the bottom, a reflective surface is in the middle, and then the top part of the disc is where the label is, and this part actually protects the data itself. The data is kept in microscopic pits in the reflective surface. This is why scratching the disc itself isn't a disaster.

Scratches don’t do much good though, because the laser used to read the disc is tuned very precisely, and if the disc is damaged, the wrong scratch or hair may refract or block the beam and make the data difficult to read.