We report the new data reproducing scheme for high density over 40GB per layer with a commercial Blu-ray
recordable disc. bER of 10-5 and 10-4 with 42.5GB and 45GB were experimentally obtained respectively using this new
data reproducing scheme which shows the possibility of achieving 50GB with a commercial single-layer Blu-ray disc.
We also propose a new evaluation parameter which is necessary for high density.
We have studied an increasing areal density with applying novel signal processing and pulse erasing writing strategy on the BD dual layer optical disc and demonstrated the feasibility for recording 66GB and 70GB per disc. As a result, we confirmed that applied technologies would allow increase recording density by 30% with commercially available disc.