A heat-assisted magnetic recording (HAMR) medium includes a substrate, a split heat-sink structure (SHSS) and a magnetic recording layer. The SHSS includes a first heat-sink layer disposed on the substrate, a heat-sink break layer (HSBL) disposed on the first heat-sink layer, and a second heat-sink layer disposed on the HSBL. The magnetic recording layer is disposed on the SHSS. The SHSS is configured to enable use of a reduced operating current of the laser while maintaining about the same write performance properties as a thermal barrier layer, heat-assisted magnetic recording (TBLHAMR) medium that includes a thermal barrier layer (TBL) and a heat-sink layer that is greater than about 20% thicker than the thickness of the SHSS. A HAMR data storage device that incorporates the HAMR medium within a HAMR disk, and a method for making the HAMR medium are also described.

Systems and methods, e.g., optical apparatuses, for digital optical information storage systems that improve the speed, signal to noise, controllability, and data storage density for fluorescent and reflective multilayer optical data storage media. The systems and methods include an optical system for a reading beam of a data channel from a moving single or multi-layer or otherwise 3-dimensional optical information storage medium that comprises at least one optical element characterized by restricting the field of view (FOV) of the reading beam on an associated image plane to 0.3 to 2 Airy disk diameters in a first direction.

Systems and methods, e.g., optical apparatuses, for digital optical information storage systems that improve the speed, signal to noise, controllability, and data storage density for fluorescent and reflective multilayer optical data storage media. The systems and methods include an optical system for a reading beam of a data channel from a moving single or multi-layer or otherwise 3-dimensional optical information storage medium that comprises at least one optical element characterized by restricting the field of view (FOV) of the reading beam on an associated image plane to 0.3 to 2 Airy disk diameters in a first direction.

Systems and methods, e.g., optical apparatuses, for digital optical information storage systems that improve the speed, signal to noise, controllability, and data storage density for fluorescent and reflective multilayer optical data storage media. The systems and methods include an optical system for a reading beam of a data channel from a moving single or multi-layer or otherwise 3-dimensional optical information storage medium that comprises at least one optical element characterized by restricting the field of view (FOV) of the reading beam on an associated image plane to 0.3 to 2 Airy disk diameters in a first direction.

Systems and methods, e.g., optical apparatuses, for digital optical information storage systems that improve the speed, signal to noise, controllability, and data storage density for fluorescent and reflective multilayer optical data storage media. The systems and methods include an optical system for a reading beam of a data channel from a moving single or multi-layer or otherwise 3-dimensional optical information storage medium that comprises at least one optical element characterized by restricting the field of view (FOV) of the reading beam on an associated image plane to 0.3 to 2 Airy disk diameters in a first direction.

A magnetic recording medium for heat assisted magnetic recording (HAMR) including in ascending vertical sequence: (i) a substrate; (ii) a first amorphous layer, a first seed layer, or a combination thereof; (iii) a heat sink layer comprising hexagonal boron-nitride grains; (iv) an optional second amorphous layer; (v) an optional second seed layer; (vi) a magnetic recording layer; (vii) an optional capping layer; and (viii) an optional overcoat layer; wherein: the magnetic recording medium has a substrate plane and a basal plane perpendicular to the substrate plane; the heat sink layer is anisotropic and has an a-axis thermal conductivity in the basal plane and a c-axis thermal conductivity in the substrate plane, wherein the a-axis thermal conductivity is greater than the c-axis thermal conductivity; and the hexagonal boron-nitride grains have an average size of at least about 10 nm in the substrate plane. Also, provided is a method of manufacturing the magnetic recording medium for HAMR.

A magnetic recording medium includes a substrate, an underlayer, and a magnetic layer including an alloy having a L1.sub.0 type crystal structure with a (001) orientation, wherein the substrate, the underlayer, and the magnetic layer are stacked in this order, the underlayer includes a first underlayer, the first underlayer is a crystalline layer that includes a material containing W as a main component and a nitride whose content ranges from 1 mol % to 80 mol %, and the nitride includes one or more elements selected from a group consisting of Al, B, Si, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, and W.