Abstract:
A two-dimensional encoder stores data on a holographic memory. The encoder encodes data of k bits (where k is an integer and k ≥ 3) into n pixels arranged two-dimensionally (where n is an integer and n ≥ 6). The encoder includes a first processing section 31 for classifying the n pixels into first and second groups of subblocks 11 and 12 using k1 bits out of the data of k bits (where k1 is an integer and k1 ≥ 1). Each of the subblocks 11 in the first group consists of m pixels (where m is an integer and m ≥ 2), and the number of the subblocks 11 forming the first group is s1 (where s1 is an integer and s1 ≥ 2). Each of the subblocks 12 in the second group also consists of m pixels, and the number of the subblocks 12 forming the second group is s2 (where s2 is an integer and s2 ≥ 1). The encoder further includes a second processing section 32 for turning ON p pixels (where p is an integer and 1 ≤ p ≤ m/2) out of the m pixels forming each subblock 11 in the first group and turning OFF all of the m pixels forming each subblock 12 in the second group using the other k2 bits of the data of k bits (where k2=k-k1).
Abstract:
There is provided volume holographic data recording media having a recording layer which is capable of recording interference fringes generated by interference of light having excellent coherence as fringes having different refractive indexes and undergoes holographic data recording by an amount of spatial shift distance of not more than 3 m which is smaller than that of conventional media.
Abstract:
ORGANOMETALLIC COORDINATION complexes exhibiting two separate, stable forms are described. Conversion from one form to the other is intramolecular, reversible, light-activated (a molecular switch) and occurs both in the solid and in solution. The two forms differ in photochemical and electrochemical characteristics (different colors and reduction potentials). The complexes can be used in information storage and for light-gathering, light-emitting, sensing and detecting applications.
Abstract:
A holographic storage media for storing digital data in the form of an interference grating is provided which includes a plurality of slabs of photorefractive material (72) arranged in a stack, with one edge thereof comprising an incident face (74). A data beam (39) having data superimposed thereon and a reference beam (38) are input to the face (74) to record a holographic image of the data in one of the slabs (72). Each of the slabs has a plurality of adjacent storage regions formed therein. The data and reference beams are disposed in a plane perpendicular to both the face (74) and the side (75) of the slabs (72), such that the reference beam (38) is confined within the slab (72) for all angles of the reference beam (38).
Abstract:
Technologies are generally related to holographic imaging. In some examples, techniques are described for generating a holographic image of an object using a plurality of light sources, a shutter, and an image sensor array. Each of the light sources is configured to generate a light beam using a respective wavelength in a different range. In various examples, an apparatus as described here may be configured to control the shutter to receive the light beams from the plurality of light sources and selectively pass each of the received light beams to provide a selected light beam. The apparatus may further include a beam splitter and a mirror unit configured to generate an object light beam and a reference light beam from the selected light beam. The apparatus may include an image sensor array configured to detect an image of interference caused by the reference light beam and the object light beam.
Abstract:
There is provided volume holographic data recording media having a recording layer which is capable of recording interference fringes generated by interference of light having excellent coherence as fringes having different refractive indexes and undergoes holographic data recording by an amount of spatial shift distance of not more than 3 m which is smaller than that of conventional media.
Abstract:
This invention relates to a technique for inducing frequency selective changes in photo-sensitive materials. It is known to store data in photo-sensitive materials using frequency selective optical data storage (FSDS). In order to improve the storage density, the present invention proposes storing data in the photo-sensitive material using a single side band technique. In one embodiment, a reference pulse is utilised having a frequeny band which encompasses only a single side band of the encoded signal. In another embodiment, a filter is utilised to filter out all frequencies apart from the single side band to be written into the material. As well as being useful for storing data in the photo-sensitive material, the single side band technique can also be used to store filter characteristics.
Abstract:
Silicate glasses for storing holographic data and for producing computer- generated holograms, including photo-darkenable-refractive (PDR) and photo-bleachable- refractive (PBR) glasses. In one embodiment, a PBR glass plate contains a photosensitive glass layer of a silver ion-exchanged holographic recording (SIHR) glass, with a base glass composition that has been ion-exchanged in an aqueous ion-exchange solution containing silver ions. The SIHR glass is uniformly darkened with darkening-light radiation, causing a refractive index change in the photosensitive glass layer upon exposure to bleaching-light radiation without any post-exposure steps. In another embodiment, an optical information recording medium includes a PDR glass plate containing SIHR glass optimized for multiplex recording and for reproducing information, which utilizes holography with darkening-light radiation as recording beams. In still another embodiment, an optical information recording medium includes a PBR glass plate containing SIHR glass optimized for multiplex recording and for reproducing information, which utilizes holography with bleaching-light radiation as recording beams.