California Institute of Technology

Siros Technologies, Inc.

Research Investment Network, Inc.

Brian H Cumpston

Matthew Lipson

Seth R Marder

Joseph W Perry

Lambertus Hesselink

Sergei L Sochava

Charles David Claude

Tokuyuki Honda

Sergei Orlov

Robert R MeLeod

Disclosed are highly efficient multiphoton absorbing compounds and methods of their use. The compounds generally include a bridge of pi-conjugated bonds connecting electron donating groups or electron accepting groups. The bridge may be substituted with a variety of substituents as well. Solubility, lipophilicity, absorption maxima and other characteristics of the compounds may be tailored by changing the electron donating groups or electron accepting groups, the substituents attached to or the length of the pi-conjugated bridge. Numerous photophysical and photochemical methods are enabled by converting these compounds to electronically excited states upon simultaneous absorption of at least two photons of radiation. The compounds have large two-photon or higher-order absorptivities such that upon absorption, one or more Lewis acidic species, Lewis basic species, radical species or ionic species are formed.

Two-photon or higher-order absorbing optical materials for generation of reactive species

An optical storage system and method having separate, independent format hologram writing and data writing mechanisms to allow optimization of data writing separately from format hologram recording. In its most general terms, the invention comprises an optical medium having a first, photoactive material responsive to a first, format hologram recording condition and a second photo-active material, responsive to a second, data writing condition, which is dispersed or dissolved in the first photoactive material. The second photoactive material may additionally be 'erasable' under a third, erasing condition. The second photoactive material is preferably in the form of microparticles, microdroplets or microcapsules which are dispersed throughout the first photoactive material. The format hologram is recorded in the first photoactive material when the optical medium is subject to the first, format hologram recording condition, and the data writing is subsequently carried out separately, in connection with the second photoactive material, under the second, data writing condition. The separate format hologram recording and bit writing functions provided by the diferent conditions make them orthogonal.

Optical data storage system and method

An optical data storage system and method comprising a photopolymer medium having generally a polymerizable monomer, an active binder, a first, hologram recording polymerization initiator, and a second, data writing polymerization initiator. The monomer is preferably a cationic ring-opening monomer. The hologram recording polymerization initiator preferably comprises a sensitizer and photoacid generator which initiate a first polymerization in the medium which defines a format hologram. The format hologram recording is carried out via interference of a signal and reference beam, with the sensitizer being specific for the wavelength(s) of the signal and reference beams. The hologram recording polymerization is only partial and does not consume all of the monomer present in the photopolymer medium. A second stage, a data writing polymerization initiator, specific to a data writing beam, locally advances polymerization at selected data storage locations to alter the previously recorded format hologram, resulting in optical data storage as localized alterations in the format hologram.

Optical storage media and method for optical data storage via local changes in reflectivity of a format grating

The present invention comprises an optical data storage system utilizing a host material and molecules that exhibit non-linear absorption dissolved therein. The non-linear absorbing molecules allow for energy in the form of heat to be generated during the optical data storage process. This heat provides for localized alterations to occur in the pre-formatted holographic grating. The non-linear feature of these molecules allow for alterations to occur at specific depths and locations within the storage medium while limiting the secondary effects on other locations within the storage medium. The molecules exhibiting non-linear absorption may be selected from the group of molecules exhibiting two-photon absorption or reverse saturable absorption. The invention also comprises a method for preparing the optical storage medium, an optical data storage device comprising the optical data storage medium and having a format hologram stored within the medium. Additionally, the invention comprises an optical data storage system and method for use thereof wherein the storage system uses the optical data storage medium described above when altering a pre-formatted holographic grating in a localized region by non-linear thermal disruption of the grating. Another embodiment of the present invention comprises an optical data retrieval system embodying the optical data storage device described above and a method for retrieving the format hologram stored on the optical data storage device of the present invention.

Method and apparatus for optical data storage using non-linear heating by excited state absorption for the alteration of pre-formatted holographic gratings

An apparatus and method for optical data storage and/or retrieval using an optical data storage medium having a spatially-modulated refractive index that can be altered locally with optical methods. Data can be written at a plurality of depths throughout the volume of the medium using a write beam and relatively simple and inexpensive optical components. The write beam stores data locally by physical distortion of the medium at discrete storage locations. The alterations can be detected as variations in the reflectivity of the storage locations using a retrieval beam.

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Sunnyvale, CA, United States of America

Brian H Cumpston