Sanyo has developed an improved blue laser diode capable of emitting a 450 milliwatt beam, which makes it powerful enough to write Blu-ray media at up to 12x with up to 4-layers.  4-layer discs are still under development, which will bring Blu-ray capacity up to 100GB per disc.  In the meantime, Sanyo plans mass-producing the new semiconductor laser diode to have stock ready for when the new drives and media to support this laser become available in the next 2 to 3 years.

This new laser diode features several improvements over current blue laser diodes, including a more stable and efficient end face protective film, to reduce the amount of light being absorbed and to improve the diode's working life.  Its cladding layer has been improved to also reduce light absorption, to give a 10% higher optical output for a given supplied current compared with the existing method.  Finally, the waveguide has been optimised to stabilise the beam position.

With the number of times companies have announced upcoming 4+ layer Blu-ray media since Blu-ray hit the market, it'll be interesting to see how long it takes for the first such media and compatible drives to finally reach the stores.