How does shorter wavelength laser light allow more information on a disc?

[ah lai]

Information is stored in a series of pits on the disc. These pits are scanned by a laser beam. An significant limitation on amount of information that can be stored on a disc is width of laser beam.

I knew why the width of laser beam is important coz diffraction effect of loght.

But, i dunoe how using shorter-wavelength laser allows more information to be stored on disc of same size...HOW?

 

[wololoh]

Well, the diffraction effects you mentioned, do they depend on wavelength? ;)