Abstract: Mastering techniques are described that can improve the quality of a master used in data storage disk manufacturing. In particular, the techniques described herein can improve resolution of the features created on the master by reducing mastering noise. The techniques include depositing a multi-layer structure adjacent a master substrate layer. The multi-layer structure includes an etch stop layer, an etch layer, and a photoresist layer. A thickness of each of the layers is selected to generate substantially no reflectivity for at least one interface of the multi-layer structure to substantially eliminate stray light effects. The photoresist layer defines a portable conformable mask (PCM) for the etch layer. The etch layer is etched through the contact mask to define a feature of the master in the etch layer. The etch stop layer thickness may be selected to be as thin as possible to reduce surface roughness of the multi-layer structure.

Abstract: The invention provides a dichroic coating for holographic media. The dichroic coating is substantially non-reflective of light at a first wavelength and substantially reflective of light at a second wavelength. A holographic recording material of the medium can be formulated to be sensitive to the first wavelength of light, but generally insensitive to the second wavelength. A probe beam at the second wavelength can be used to interrogate the medium and identify tracking features.

Abstract: In one embodiment, holographic data storage medium includes a first thermoplastic substrate portion having a thickness less than approximately 2 millimeters and a second thermoplastic substrate portion having a thickness less than approximately 2 millimeters. A holographic recording material may be sandwiched between the first and second thermoplastic substrate portions. By making thermoplastic substrate portions sufficiently thin, edge wedge problems can be avoided.