Sergei L. Sochava

Microholographic multilayer optical disk data storage

Micrometer-sized reflection holograms can be written into a rapidly rotating homogeneous photopolymer disk at the focus of a high-numerical-aperture beam and its retroreflection to implement high-capacity multilayer digital data storage. This retroreflection is generated by an optical system with positive unity magnification to ensure passive alignment of the counterpropagating beam. Analysis reveals that the storage capacity and transfer rate of this bit-based holographic storage system compare favorably with traditional page-based systems but at a fraction of the system complexity and cost. The analysis is experimentally validated at 532 nm by writing and reading 12 layers of microholograms in a 125-microm photopolymer disk continuously rotating at 3600 rpm. The experimental results predict a capacity limit of 140 Gbytes in a millimeter-thick disk or over 1 Tbyte with the wavelength and numerical aperture of Blu-Ray.

Synthesis and characterization of photochromic organic films for holographic recording

Polymer films doped with 2-(5, 5-dimethyl-3-styryl-cyclohex-2-enylidene)-malononitrile chromophore and various sensitizers have been prepared and characterized. The material exhibits high sensitivity in the red region (S=0.26 cm(2)/J at lambda=633 nm), a large dynamic range (Dn=-0.05) , and large transient two-beam coupling gain (G=110 cm(-1)) . Self-diffraction effects, such as energy and phase coupling, and photoinduced scattering are studied.

Holographic Storage without Holography: Optical Data Storage by Localized Alteration of a Format Hologram

We propose and demonstrate multi-layer storage in holographic photopolymer by locally altering the reflectivity of a factory-written reflection hologram at the focus of a single objective lens. Linear, two-photon and thermal writing mechanisms are demonstrated.

Micro-Holographic Multi-Layer Optical Disk Data Storage

We demonstrate 12-layer storage of 5.84 Gbits per square inch via micro-holograms written and read at 0.532 nm from a 125 micron photopolymer disk continuously rotating at 3600 RPM. Scaling predicts a potential TByte capacity.