Anti-reflective coating for holographic data storage media
AssigneeImation Corp.
InventorFrank E. Aspen
Life of this patent
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Abstract
A holographic data storage medium having an anti-reflective coating is described. The anti-reflective coating can be made to reduce reflectivity for S-polarized light over a wide range of incident angles. Moreover, the anti-reflective coating can be made to have a sufficiently high transmittance for the S-polarized light. The coating may improve performance of the holographic data storage medium, and can facilitate higher storage densities than can be achieved without the coating.
Claims22
A holographic data storage medium including an anti-reflective coating on a surface of the medium, wherein the anti-reflective coating causes the medium to have less than 1.0 percent reflectivity of S-polarized light at incident angles greater than approximately 50 degrees relative to a line normal to the surface of the medium.
A holographic data storage system comprising:
- a laser that produces at least one laser beam;
- optical elements through which the laser beam passes;
- a holographic recording medium including an anti-reflective coating on a surface of the medium, wherein the anti-reflective coating causes the medium to have less than 1.0 percent reflectivity of S-polarized light at an incident angle greater than approximately 50 degrees relative to a line normal to the surface of the medium;
- and
- a data detector that detects a hologram reconstructed when the laser beam illuminates the holographic recording medium at an incident angle greater than approximately 50 degrees relative to a line normal to the surface of the medium.
A method comprising:
- forming an anti-reflective coating on a holographic data storage medium to limit reflectivity of S-polarized light at incident angles greater than approximately 50 degrees relative to a line normal to the surface of the medium to less than approximately 1.0 percent.
Dependencies are inferred from the claim text.