Experimental characterization for the binary two-dimensional optical storage channel

A new and challenging concept for optical storage is being developed, in which the information written on the disc has a two-dimensional characteristic, with the aim of realizing an increase of a factor of two in data density and a factor of ten in data rate over the current 3rd generation of optical storage (Blu-Ray Disc, BD). Experimental channel characterization provides insight into the magnitude of intersymbol interference, signal levels, modulation and noise distribution from the measured signal waveform. This information is used to evaluate the quality of the mastered discs, and provide feedback in the optimization process. It also yields essential input to the actual design of the signal processing solutions. The stages involved in characterizing the channel are downsampling and model fitting using a scalar diffraction model. The information gathered from channel characterization is demonstrated with experimental measurements from discs with an initial density of 1.4/spl times/BD using the same physical read-out system (blue laser and high-NA lens).