It's an optical disc technology still in the childhood stages of research called as the collinear holography, would soon gain upper hand over the existing technologies like the blue-ray and HD DVD optical disc systems with respect to its storage capacity. Consisting of a blue-green laser and a red laser collimated in a single beam, the blue-green laser reads data encoded as laser interference fringes from a holographic layer near the top of the disc while the red laser is used as the reference beam and to read servo information from a regular CD-style aluminium layer near the bottom.