"Optical road map in mass storage technologies"

Optical mass storage technologies have found solutions to make low cost, high reliable and compatible memories in the last 20 years. The technology of optical disc storage is based mainly on these parameters. The wavelength of the laser diode (780 nm for CD, 650 nm for DVD and 405 nm for the BD: Blu-ray Disc). The numerical aperture of the focusing objective lens (0.45 for CD, 0.6 for DVD and 0.85 for BD). The information recording material of the disc (magnetic material, phase change material or dye polymer). The coding algorithms (including error coding) and the signal processing