Hitachi has developed a prototype four layer Blu-Ray disc that includes a 100GB storage capacity. Hitachi unveiled the disc at CEATEC JAPAN 2007.
Apparently, what’s really special about Hitachi’s latest prototype is that the company has used a standard Blu-Ray drive optical head that’s only slightly modified making it possible to read and write data across the four 25GB layers. It seems this will only require a firmware update to make current drives compatible. In the previous 100GB discs of various other companies, a specially developed optical head in the player had to be developed to read the disc
Reportedly, the hardware manufacturer is now in the move to stabilize signal quality before launching it into the commercial market.
In addition, Hitachi is also exploring an eight layer disc that can hold 200GB of data; however it has faced problems with reflections decreasing signal strength across the eight layers, which it is working to set right.