In Sony's system (used on their proprietary Optical Disc Archive system which relies on Archival Disc, itself based mostly on Blu-ray) the drive has four optical pickups, two on each side of the disc, Spin win with Free Slots each pickup having two lenses for a total of 8 lenses and laser beams. The ExpressCard customary specifies two type elements, ExpressCard/34 (34 millimetres (1.3 in) extensive) and ExpressCard/54 (54 mm (2.1 in) huge, in an L-shape)-the connector is the same on both (34 mm wide).

Both layers are accessible from the same facet, however require the optics to alter the laser's focus. Because the depth of the pits is approximately one-quarter to 1-sixth of the laser's wavelength, the reflected beam's section is shifted in relation to the incoming beam, inflicting mutual destructive interference and free slots decreasing the reflected beam's intensity. In Zen's system (developed together with Sanyo and licensed by Kenwood), a diffraction grating is used to cut up a laser beam into 7 beams, which are then centered into the disc; a central beam is used for focusing and monitoring the groove of the disc leaving 6 remaining beams (three on both aspect) that are spaced evenly to learn 6 separate portions of the groove of the disc in parallel, effectively rising learn speeds at lower RPMs, reducing drive noise and stress on the disc.

Zen Technology and Sony have developed drives that use several laser beams simultaneously to learn discs and write to them at increased speeds than what can be possible with a single laser beam. Disc recording is restricted to storing files playable on shopper appliances (movies, music, etc.), relatively small volumes of information (e.g. a regular DVD holds 4.7 gigabytes, however, increased-capacity codecs equivalent to multi-layer Blu-ray Discs exist) for native use, and information for online Slots distribution, but solely on a small scale; mass-producing giant numbers of similar discs by pressing (replication) is cheaper and faster than particular person recording (duplication).

With an choice within the optical disc authoring software program, optical disc writers are capable of simulate the writing process on CD-R, CD-RW, DVD-R and DVD-RW, which permits for testing akin to observing the writing speeds and patterns (e.g. constant angular velocity, free slots constant linear velocity and P-CAV and Free slots no download Z-CLV variants) with totally different writing velocity settings and testing the very best capacity of an individual disc that would be achievable utilizing overburning, without writing any knowledge to the disc.

Traditional single layer (SL) writable media are produced with a spiral groove molded within the protective polycarbonate layer (not in the information recording layer), to guide and synchronize the velocity of recording head.

The first groove spiral usually starts on the inner edge and free online slots extends outwards, while the second groove begin on the outer edge and extends inwards.