Duallayer

Duallayer is a descriptive term used across several domains to indicate a system composed of two functional layers. It does not correspond to a single standardized technology, but rather to configurations in fields such as optical storage, coatings and membranes, and computing or engineering architectures where two layers collaborate to perform a task.

In optical media, dual-layer discs contain two data layers on a single side. This arrangement increases storage capacity without increasing disc diameter. DVD dual-layer discs typically hold about 8.5 GB, while Blu-ray dual-layer discs hold up to 50 GB. Readout involves adjusting the laser focus to access the second layer, sometimes with changes in laser power or focusing optics.

In materials science, dual-layer coatings or membranes combine two materials with distinct properties to improve barrier performance, wear resistance, or selectivity. Examples include dual-layer anti-reflective coatings and protective or separation membranes where the outer and inner layers provide complementary functions.

In computing and engineering, dual-layer or two-layer configurations appear in architectures separating concerns, such as presentation and data layers, or in physical insulation schemes in cables and components. The term is commonly used as dual-layer in formal specifications, while duallayer may appear in trademarks or informal references.

The meaning of duallayer is context-dependent and should be clarified by the domain and accompanying documentation. In many cases, the concept is conveyed with the more common term dual-layer, but variations in spelling can occur in product naming or informal discourse. See also dual-layer and two-layer concepts in related fields.