Abstract text

A holographic disc comprises a multilayer right-circular frustum. The frustum includes a substrate layer having an inner surface and an outer surface. A reflective track layer is formed on the inner surface of the substrate layer. A first gap layer overlies the reflective track layer. A dichroic mirror layer overlies the first gap layer. A second gap layer overlies the dichroic mirror layer. A holographic recording layer overlies the second gap layer. A cover layer overlies the holographic recording layer. The cover layer has an inner surface in contact with the holographic recording layer and an outer surface. The frustum has a major diameter and a minor diameter. In one embodiment of the multilayer right-circular frustum, the outer surface of the said outer surface of the cover layer defines the minor diameter and the outer surface of the substrate layer defines the major. In another embodiment, the outer surface of the substrate layer defines the minor diameter and the outer surface of said the cover layer defines the major diameter.