Abstract: Manufacturing of a part by local irradiation of a material that can be sintered, melted or photopolymerized, by: providing a volume of the material for manufacturing the part and compressing the volume by applying a pressure; defining, in the volume, a plurality of different target volumes, the combined target volumes defining the part to be manufactured; for each target volume, maintaining the pressure applied to the volume and simultaneously irradiating the target volume with at least two continuous beams that converge in the target volume; releasing the obtained part from the rest of non-irradiated material. The material is partially transparent to the beams; the energy applied to the target volume by each beam is greater than Ethreshold, the sum of the energies applied to the target volume by each of the beams is greater than or equal to Etransformation threshold.

Abstract: A device and method of forming a three-dimensional component includes filling a reservoir (26) with a volume of curable resin (30), the resin configured to undergo a first reaction to form a first product when exposed to light (42) of a first wavelength and to undergo a second reaction to form a second product when exposed to light (62) of a second wavelength. The presence of the first and second products at a common location in the resin causes a third reaction that results in a solid polymer at the common location. The method further includes directing a first light source (34) of the first wavelength into the reservoir, directing a second light source (54) of the second wavelength into the reservoir such that the first and second light sources intersect at a first predetermined location (78) within the reservoir, and allowing the third reaction to form the solid polymer at the first predetermined location.

Abstract: A multi-beam volumetric resin curing system and method for whole-volume additive manufacturing of an object includes a bath containing a photosensitive resin, a light source for producing a light beam, and a spatial light modulator which produces a phase- or intensity-modulated light beam by impressing a phase profile or intensity profile of an image onto a light beam received from the light source. The system and method also include projection optics which then produces multiple sub-image beams from the modulated light beam which are projected to intersect each other in the photosensitive resin to cure select volumetric regions of the resin in a whole-volume three-dimensional pattern representing the object.

Abstract: Methods, systems, and devices for particle characterization by optical phase modulation and detection of aerosol backscattering. In some aspects, a compact and cost effective particle detector device to measure the aerosol density and its size distribution by backscattered focusing using projected optical modified field distribution imaging into the aerosol medium (air). The disclosed device can be used in a variety of scientific and industrial applications, e.g., such as a particle sensor for automobiles able to detect harmful pollution which may then be filtered from the car cabin, or warnings provided to the driver. The device can also capture and store data, enabling detailed pollution maps of various roadways in real-time.

Abstract: Quick optical DRAM reset and data erasure can be performed during power down (power cycling) or chip cooling and removal from the socket. In this way cold boot attacks on DRAM secret information are prevented using simple and cheap embodiment. In wafer level packaging (chip scale package) die is usually on top (flip-chip) and metal interconnections does not interfere with penetrating light during chip illumination. IR light penetrates through chip's thin epoxy on top and it is absorbed in the die, near active layer, and generates electron-hole pairs. Electron-hole pairs diffuse to chip active layer and generate discharging photocurrents in PN junctions connected to DRAM capacitors.

Abstract: Systems and methods for driving a non-volatile memory device in a standby operating condition are disclosed. A standby detection circuit detects whether the non-volatile memory system is in a standby condition. In response to determining that the non-volatile memory system is in a standby condition, a bias control circuit provides bias currents to drivers of the non-volatile memory system in a standby mode.

Abstract: A system and method of operating a dual-beam detection system of a holographic data storage disc, including: impinging a data beam on a data layer of the holographic data storage disc; impinging a tracking beam on a tracking element of the holographic data storage disc; detecting a reflection of the tracking beam from the tracking element; and coordinating position of the data beam relative to the tracking beam.

Abstract: The present invention relates to photochromic materials that include one or more indeno-fused naphthopyrans that have particular groups at the 7, 11, and 13 positions thereof, and at the position alpha to the oxygen of the pyran ring thereof. With some embodiments, hydrogen or an alkoxy group is bonded to the 7 position, an optionally substituted phenyl is bonded to the 11 position, two alkyl groups are bonded to the 13 position, and two optionally substituted phenyl groups are bonded to the position alpha to the oxygen of the pyran ring of the indeno-fused naphthopyran compound. The 13 position of the indeno-fused naphthopyrans is free of ether groups in which an ether oxygen is bonded to the 13 position, and hydroxyl. The present invention also relates to photochromic articles and compositions that include such indeno-fused naphthopyrans.

Abstract: A non-volatile programmable electro-optical element alters absorption characteristics of an optical medium that comprises a doped transition metal oxide material including F-centers. The F-centers are electrostatically moved into or out of the regions containing a wavefunction of an optical beam. A specific F-center profile in the transition metal oxide material may be programmed into the optical medium. The F-center profile alters an absorption profile within the optical medium. The spectral range for transmission of electromagnetic radiation in the optical medium may be tailored by the F-centers. Once the absorption profile is set by an electrical signal, the optical element maintains its state even when the electrical signal is turned off. Thus, the programming node may be disconnected from a power supply network, thereby enabling a low power operation of the electro-optical element. The inventive electro-optical element may be employed for both the visible and the infrared wavelength spectrum.

Abstract: A semiconductor memory device operates by using a fixed power and a variable power. The device includes a plurality of word lines which select rows of a memory cell array, a plurality of word line drivers each of which is connected to a corresponding one of the word lines and includes a first CMOS gate, a first cutoff switch which is connected between a fixed power terminal and a power terminal of the first CMOS gate and cuts off the fixed power in a sleep mode, a switching circuit which is connected to the plurality of word lines and connects the plurality of word lines to a ground terminal in the sleep mode, and a power control circuit which generates the variable power by using the fixed power and sets the variable power to 0 V in the sleep mode.

Abstract: Various non-limiting embodiments of the present disclosure relate to photochromic materials comprising a reactive substituent. For example, the present disclosure contemplates photochromic materials, such as photochromic naphthopyrans and indeno-fused naphthopyrans having a reactive substituent comprising a reactive moiety linked to the photochromic naphthopyran by one or more linking groups. In certain non-limiting embodiments, the reactive moiety comprises a polymerizable moiety. In other non-limiting embodiments, the reactive moiety comprises a nucleophilic moiety or an electrophilic moiety. Other non-limiting embodiments of the present disclosure relate to photochromic articles, compositions, and methods of making the photochromic articles, wherein the photochromic articles and compositions comprise the photochromic naphthopyrans described herein.

Abstract: A FIFO design interfaces a sender subsystem and a receiver subsystem operating on different time domains. The sender subsystem and the receiver subsystem may be synchronous or asynchronous. The FIFO circuit includes a put interface configured to operate in accordance with the sender time domain and get interface configured to operate in accordance with the receiver time domain. The FIFO circuit includes an array of cells having a register and state controller indicative of the state of the cell. Each cell also has a put component part configured to operate according to the sender time domain including a put token passing circuit and put controller circuit. Each cell has get component part configured to operate according to the receiver time domain including a get token passing circuit and a get controller circuit. A mixed-clock relay station design interfaces a sender subsystem and a receiver subsystem working at different time domains, and where the latency between sender and receiver is large.

Abstract: An apparatus including a contact on a substrate, a dielectric material overlying the contact, a phase change element overlying the dielectric material on a substrate, and a heater element disposed in the dielectric material and coupled to the contact and the phase change element, wherein a portion of the dielectric material comprises a thermal conductivity less than silicon dioxide. A method including introducing over a contact formed on a substrate, a dielectric material, a portion of which comprises a thermal conductivity less than silicon dioxide, introducing a heater element through the dielectric material to the contact, and introducing a phase change material over the dielectric material and the heater element.

Abstract: The invention provides photochromic bis-naphthopyran compounds as well as methods for their manufacture and their use. The bis-naphthopyran compounds of the invention exhibit a wide range of color, i.e., from pink to purple to blue gray, upon activation by a source of UV light. Additionally, the bis-naphthopyran compounds of the present invention exhibit broad coloration ability, fast response as to both color change on activation and return to original color, and good fatigue-resistance.

Abstract: Techniques for continuously programming a coherent transient spatial-spectral optical signal processor involve the repeated application of two or more spatially distinct optical programming pulses to a non-persistent hole-burning material to write an accumulated, spatial-spectral population grating with low intensity optical pulses as compared to single shot programming. An optical data stream is introduced on a processing beam, resulting in a processor output signal spatially distinct from all the processing pulses. Programming and processing take place simultaneously, asynchronously and continuously. For accumulated gratings, the frequency stability of the optical source is an important consideration.

Abstract: Selected domains, normally 2×103×2×103 such domains arrayed in a plane, within a three-dimensional (3-D) volume of radiation-sensitive medium, typically 1 cm3 of spirobenzopyran containing 2×103 such planes, are temporally and spatially simultaneously illuminated by two radiation pulses, normally laser light pulses in various combinations of wavelengths 532 nm and 1024 nm, in order, dependent upon the particular combination of illuminating light, to either write binary data to, or read binary data from, the selected domains by process of two-photon (2-P) interaction/absorption. One laser light pulse is preferably directed to illuminate all domains during its propagation along one directional axis of the volume. The other laser light pulse is first spatially encoded with binary information by 2-D spatial light modulator, and is then (i) directed and (ii) time sequenced to intersection with the other light pulse in a locus of intersection domains.

Abstract: High density, photon-gated persistent spectral holeburning is effectuated in rare earth doped II-VI compounds such as MgS, CaS, BaS and SrS. Two-photon ionization of rare earth ions is performed, selected by a narrow band laser, producing narrow regions of reduced absorption (optical holes) in the absorption spectrum of a rare earth ion. These holes are useful for such applications as high density memory (especially, high density re-writable or photo-erasable memory), spectral holographic memory, communication, etc., no and demonstrate great survivability over reading cycles, thermal cycles and elevated temperatures. The embedment of the rare earth doped II-VI compound in a matrix comprising a polymeric material (such as PMMA), prior to the effectuation of the holeburning, may be advantageous for many embodiments. Inventive practice has successfully burned two hundred forty photon gated spectral holes in the zero phonon line (ZPL) of the 4f-5d transition of Eu2+ in a magnesium sulfide host.

Abstract: High density, photon-gated persistent spectral holeburning is effectuated in rare earth doped II-VI compounds such as MgS, CaS, BaS and SrS. Two-photon ionization of rare earth ions is performed, selected by a narrow band laser, producing narrow regions of reduced absorption (optical holes) in the absorption spectrum of a rare earth ion. These holes are useful for such applications as high density memory (especially, high density re-writable or photo-erasable memory), spectral holographic memory, communication, etc., and demonstrate great survivability over reading cycles, thermal cycles and elevated temperatures. The embedment of the rare earth doped II-VI compound in a matrix comprising a polymeric material (such as PMMA), prior to the effectuation of the holeburning, may be advantageous for many embodiments. Inventive practice has successfully burned two hundred forty photon gated spectral holes in the zero phonon line (ZPL) of the 4f-5d transition of Eu2+ in a magnesium sulfide host.

Abstract: Three-, and four-dimensional (“3-D” and “4-D”) volume radiation memories store multiple binary bits of information—typically about five to ten and more typically eight such bits—in the same physical volumes on several different photochromic chemicals co-located in the volume. Each of the multiple photochromic chemicals is individually selectively written with an individually associated pair of radiation beams of an appropriate combined frequency—i.e., a “color”—and energy by a process of two-photon (“2-P”) absorption. All the multiple information bits that are stored within all the photochromic chemicals in each addressable domain are read in common, and induced to simultaneously fluoresce, again by process of 2-P absorption.

Abstract: A method for optimizing the interaction of a resonant material having generalized crystal symmetry with a beam or beams of radiation. The invention includes determining a special direction relative to the axes of crystal symmetry of the material and polarizing the interaction radiation beam along this direction. The polarized radiation beam is propagated through the material perpendicular to this special direction. The method and system are used in any application which involves the coherent interaction of optical radiation beams or fields with resonant ion-doped or molecular crystals of various types. Coherent interaction of optical radiation beams or fields with resonant ion-doped or molecular crystals of various types includes the phenomena of optical coherent transients, spectral hole burning, and spatial-spectral holography (also called time and space domain holography) and provides the basis for optical-electronic devices. Such applications include computer and communications networks.

Abstract: The present invention relates to the field of optical recording materials, in particular, fluorescent compounds and matrices suitable for use in optical memory systems, including three dimensional optical memory systems for READ ONLY MEMORY (ROM). In particular, nonfluorescent Rhodamine B lactams are photochemically transformed into fluorescent Rhodamine B derivatives.

Abstract: An optical memory system includes memory cells which utilize synthetic DNA as a component of the information storage mechanism. In the preferred embodiment, memory cells contain one or more chromophoric memory units attached to a support substrate. Each chromophoric memory unit comprises a donor, an acceptor and, at some time during its existence, an active quencher associated with the donor and/or the acceptor. The donor and the acceptor permit non-radiative energy transfer, preferably by Forster energy transfer. To write to the memory cell, the quencher is rendered inactive, preferably by illumination with ultraviolet light. To read, the chromophoric memory units in a read portal are illuminated, and the read illumination is detected. In the preferred embodiment, multiple chromophoric memory units having resolvable read properties are contained within a single read portal. In this way, a multibit word of data may be read from a single diffraction limited read portal.

Abstract: The present invention relates to the field of optical recording materials, in particular, fluorescent compounds and matrices suitable for use in optical memory systems, including three dimensional optical memory systems for READ ONLY MEMORY (ROM). In particular, nonfluorescent Rhodamine B lactams are photochemically transformed into fluorescent Rhodamine B derivatives.

Abstract: Disclosed is an organic thin film device having an organic thin film consisting of a mixed-stacked charge-transfer complex, wherein the organic thin film contains n species of donor molecule D.sub.1 . . . D.sub.n and m species of acceptor molecule A.sub.1 . . . A.sub.m and forms mixed crystal represented by (D.sub.1).sub.x1 . . . (D.sub.n).sub.xn -(A.sub.1).sub.y1 . . . (A.sub.m).sub.ym and the combinations of a donor molecule and an acceptor molecule consist of a group forming ionic complex crystal and a group forming neutral complex crystal.

Abstract: An optical memory system includes memory cells which utilize synthetic DNA as a component of the information storage mechanism. In the preferred embodiment, memory cells contain one or more chromophoric memory units attached to a support substrate. Each chromophoric memory unit comprises a donor, an acceptor and, at some time during its existence, an active quencher associated with the donor and/or the acceptor. The donor and the acceptor permit non-radiative energy transfer, preferably by Forster energy transfer. To write to the memory cell, the quencher is rendered inactive, preferably by illumination with ultraviolet light. To read, the chromophoric memory units in a read portal are illuminated, and the read illumination is detected. In the preferred embodiment, multiple chromophoric memory units having resolvable read properties are contained within a single read portal. In this way, a multibit word of data may be read from a single diffraction limited read portal.

Abstract: Apparatus and methods are disclosed for spatially routing an optical pulse (data pulse) of an electromagnetic radiation and containing a specific address temporal profile and possibly additional data. Routing generally involves a unit of active material that is programmed using one or more input beams or pulses of the electromagnetic radiation providing address (i.e., waveform-discriminating) and directional (i.e., pulse routing) information to the active material. During programming, a spatial-spectral grating is created by optical interference on or in the active material of the input pulses encoding the address and directional information pertinent to the data pulse.

Abstract: The recording method and apparatus according to this invention is an "optical recording method utilizing a simulated photon echo" in which information is recorded by irradiating data a.d record excitation lights at the same time or at different times on the same location of a recording medium, and in which the delay time of a record excitation light electric field and a data light electric field is recorded as the information by use of a common incoherent light split into two equal parts: the data light and the record excitation light. In the reproducing method and apparatus according to this invention, reproducing excitation and probe lights are illuminated on the recording medium and the stimulated photon echo light emitted from the medium by illumination of the reproducing excitation light overlaps the probe light. The "stimulated photon echo" reproducing the information is utilized by converting the synthetic light obtained from the overlap into an electrical signal at a photo detector.

Abstract: A device for optically storing and retrieving information incorporating a cadmium fluoride crystal. Using focused ionizing radiation, patterns can be formed in the crystal by the creation of color centers and/or intrinsic luminescence quenched areas. The stored information can then be retrieved by irradiating the crystal with visible light, ultraviolet light, ionizing radiation or combinations thereof. The device and the storage technique allows the storage of various different levels of information, the different levels being retrievable by using different irradiating media and magnifications of the retrieved information. The device and technique also allows the information to be stored for a predetermined period of time.

Abstract: The recording method and apparatus according to this invention is an "optical recording method utilizing a simulated photon echo" in which information is recorded by irradiating data and record excitation lights at the same time or at different times on the same location of a recording medium, and in which the delay time of a record excitation light electric field and a data light electric field is recorded as the information by use of a common incoherent light split into two equal parts: the data light and the record excitation light. In the reproducing method and apparatus according to this invention, reproducing excitation and probe lights are illuminated on the recording medium and the stimulated photon echo light emitted from the medium by illumination of the reproducing excitation light overlaps the probe light. The "stimulated photon echo" reproducing the information is utilized by converting the synthetic light obtained from the overlap into an electrical signal at a photo detector.

Abstract: Methods and apparatii are described for information storage in photoconductive film of single layer composition by irradiation of memory elements simultaneously with application of an electric field. Information is stored as trapped charge accumulations in the film when the irradiation is removed, but trapped charge can be released by subsequent irradiation. Repeated information storage, followed by erasure, returns the films to their original state without degradation.

Abstract: The multi-dimensional optical memory utilizes the wavelength and intensity dimensions to effect a high density record. With incorporation of a broadband light source, scanning monochromator and photo detector array, a high speed random access optical memory system is realized. The system is executed in terms of a silicon based manufacturing technology allowing advantages of low cost and small physical size resulting from photolithographic batch-processing producibility.

Abstract: A method and apparatus for coherent time-domain optical data storage utilizing a randomizing phase modulation to increase storage capacity. A laser (10) generates write. read, and data pulses which are applied to an acousto-optic modulator (11), which modulates the pulses according to a modulation signal received from a radio-frequency modulator (12), and the modulated pulses are applied to the storage medium (13). The data signal to be recorded on the storage medium is subjected to spread-spectrum modulation, and in particular to pseudo-random phase modulation. The RF-modulator (12) modulates the write and read pulses with a frequency-chirping modulation and modulates the data pulse with the spread-spectrum modulated data signal before applying the respective pulses to the storage medium. The result is that a significantly longer data signal may be effectively recorded on the optical storage medium for a given characteristic de-phasing time of the medium.

Abstract: The invention relates to an optical computing element for use in an optical computer utilizing computing light rays having a plurality of wavelength components. The optical computing element comprises a photo-chemical hole burning element which functions as a wavelength selecting filter of the computing light rays. Therefore, the optical computer using the photo-chemical hole burning element of the invention can perform arithmetic operations by taking advantage of differences in optical wavelength. The computer can efficiently perform bulky arithmetic processing, and can also speedily perform arithmetic operations through simultaneous parallel processing for information.

Abstract: Methods and apparatii are described for information storage in photoconductive film of single layer composition by irradiation of memory elements simultaneously with application of an electric field. Information is stored as trapped charge accumulations in the film when the irradiation is removed, but trapped charge can be released by subsequent irradiation. Repeated information storage, followed by erasure, returns the films to their original state without degradation.

Abstract: Selected domains, normally 10.sup.3 .times.10.sup.3 such domains arrayed in a plane, within a three-dimensional (3-D) volume of active medium, typically 1 cm.sup.3 of spirobenzopyran containing 10.sup.2 such planes, are temporally and spatially simultaneously illuminated by two radiation beams, normally laser light beams in various combinations of wavelengths 532nm and 1024nm, in order, dependent upon the particular combination of illuminating light, to either write binary data to, or read binary data from, the selected domains by process of two-photon (2-P) absorption. One laser light beam is preferably directed to illuminate all domains of the selected plane in and by a one-dimensional spatial light modular (1-D SLM). The other laser light beam is first spatially encoded with binary information by 2-D SLM, and is then also directed to illuminate the domains of the selected plane.

Abstract: The invention relates to an optical computing element for use in an optical computer utilizing computing light rays having a plurality of wavelength components. The optical computing element comprises a photo-chemical hole burning element which functions as a wavelength selecting filter of the computing light rays. Therefore, the optical computer using the photo-chemical hole burning element of the invention can perform arithmetic operations by taking advantage of differences in optical wavelength. The computer can efficiently perform bulky arithmetic processing, and can also speedily perform arithmetic operations through simultaneous parallel processing for information.

Abstract: A material for optical recording by utilizing the photochemical hole burning is disclosed. The optical recording material is a composition comprising a watersoluble deuterated polymer as a host component and a water-soluble organic pigment dispersed in the host component as a guest component. By virtue of the deuteration of the host component, the tunnel effect of the hydrogen atoms in the host component is prevented, so that the hole width is narrowed. Thus, the wavelength multiplicity is increased.

Abstract: A magneto-optic memory device, such as a magneto-optic disk or magneto-optic card having a pair of opposed substrates at least one of which is transparent. Between the substrates is a magneto-optic memory layer made of a stack of dielectric film, a rear earth-transition metal alloy thin film, a dielectric film and a light reflecting film built on the surface of the transparent substrate opposed to the other substrate. An adhesive layer covers the memory layer and bonds the transparent substrate to the other substrate. Lastly, a metal nitride film interposed between the light reflecting film of the memory layer and the adhesive layer.

Abstract: Phase modulation is used to record data in a spectral hole burning material. A laser and a phase modulator are used to generate both a reference pulse and a phase modulated data pulse to the material. The data is recorded as spectral holes in the absorption spectrum of the material. In order to read the data, a second reference pulse is generated which creates an echo pulse from the material. This echo pulse is combined with a frequency shifted comparator pulse in order to generate a heterodyne signal. A phase sensitive demodulator detects the phase transitions in the heterodyne signal and generates a digital signal representative of the data recorded.

Abstract: Data storage methods and apparatus are disclosed that utilize a swept-carrier optical approach with an inhomogeneously broadened absorber material having multiple special storage cells. Data are encoded on a data pulse by appropriately modulating the data pulse. Data storage in a storage cell is effected by exposing the cell to the data pulse and a reference pulse cotemporal with the data pulse. Both the data and reference pulses are frequency-chirped across the inhomogeneously broadened bandwidth of the absorber material, the data pulse being chirped at a frequency that is offset relative to the reference pulse. Data retrieval from the storage cell is performed by exposing the cell to a read pulse which causes the cell to produce a signal pulse comprising the encoded data. The read pulse can have a temporal profile that produces a signal pulse shaped either similarly to the data pulse or as a mirror image of the data pulse.

Abstract: A frequency multiple outgoing light is obtained by intensity-modulating a frequency multiple incident light in frequency domain, after irradiating a pump beam to an optical recording medium consisting of photochromic material and the like to generate optical Stark effect thereon and shifting the light absorption spectrum of the optical recording medium by optical Stark effect.

Abstract: An organic thin film element is disclosed which has an organic thin film consisting of a mixed stacked charge-transfer complex of donor and acceptor molecules, wherein the organic thin film is made neutral by forming the mixed stacked charge-transfer complex which is ionic under the bulk state into a thin film.

Abstract: A wavelength selective optical recording and reproducing method includes an optical recording and reproducing step of information composed of time series signals on a recording medium having recording tracks as position series signals with light having a variable wavelength while switching the wavelength between predetermined values.

Abstract: A wavelength multiplexed optical recording material is disclosed wherein a photosensitive material including substituted porphine, such as tetra(pentafluorophenyl) porphine or tetra(4-methoxyphenyl) porphine, is uniformly dispersed into an optically transparent dispersion medium. When such wavelength multiplexed optical recording material is cooled to a temperature of liquid helium and irradiated with a laser beam, a large number of holes of narrow width are formed in an inhomogenous absorption band under the phenomenon of photochemical hole burning. As compared to unsubstituted porphine, the above porphine derivatives give an improved recording sensitivity and narrow hole width.

Abstract: An image processing apparatus having a third-order nonlinear stimulated photon echo medium (1). The photon echo medium (1) can store large numbers of images in the form of a Fourier transformed pattern by spectral modulation. The spectral modulation is carried out by sending optical pulses in an optical pulse train having (or not having) image information to the medium (1) so that the population in the ground and excited states are modulated after the passage of the pulse trains and pulses. The Fourier transformed pattern is converted back to temporal modulation, consisting of a sequence of echo pulses that reproduce the original data pulse train. By using the apparatus, ultrafast operation such as convolution and correlation between a number of reference images and a test image can be achieved.

Abstract: Apparatus for storage and retrieval of digital data includes a multidimensional holographic storage medium for storing phase holographic images representative of the digital data. Selected regions of the medium are independently addressable by a beam of light. The storage medium is a spectral hole burning material having absorption regions independently addressable by selected frequencies of light, and includes selectively bleached absorption structures forming frequency channels. An external electric field of selected voltage can be applied to the storage medium to induce Stark effect broadening of the spectral holes, so that at a given frequency of light, a different phase hologram can be stored for each of a plurality of voltages, whereby multiple phase holograms can be stored for each frequency of light. Alternatively, physical stress can be applied to the storage medium to induce a stress field and associated broadening.

Abstract: A three-dimensional object producing method, and the apparatus for carrying it out, of the type in which a beam is irradiated on a liquid surface of a liquid photo-curable resin to form a succession of cured resin layers corresponding to successive cross-sectional laminae of the three-dimensional object and step-wise moving the cured resin layers as they are formed to build up a three-dimensional copy of object, wherein the improvement of the method comprises vector-scanning the beam on a first layer of photo-curable resin along one or more paths corresponding to the contour or contours of a first one of the cross-sectional laminae of the object, thereafter, raster-scanning the beam on one or more layers of photo-curable resin which are subsequent to the first layer of photo-curable resin, and alternating repeating these different scanning steps until a complete copy of the object is thereby produced.

Abstract: An erasable optical disk drive system is disclosed which utilizes an electron trapping media coated on the disk surface to store data in the form of light energy. Data is written onto the disk, which is contained in a light-tight contamination-free environment similar to a Winchester hard disk drive system, using a near infrared light laser beam. Data is read from the disk using a visible light laser beam. The entire optical disk drive system is designed to fit within a standard mini or 51/4 inch disk drive form factor for personal computers.

Abstract: An optical data storage medium, comprising; (a) an amorphous matrix; and (b) guest molecules dispersed in the amorphous matrix, the guest molecules consisting essentially of electron donors and electron acceptors which are in a solid state at room temperature, the optical data storage medium having an inhomogeneously broadened absorption band due to a distribution of local environments around the guest molecules dispersed in the amorphous matrix, such that the optical data storage medium is capable of storing at least two bits of data in a frequency domain by virtue of an irreversible multiphotonic electron transfer reaction consisting of more than one photon process, in which at least one electron is transferred from the electron donors to the electron acceptors.

Abstract: An apparatus in accordance with the present invention sequentially fixes the wavelength of a light beam irradiated from a light source whose oscillation wavelength sequentially varies to a plurality of different wavelengths to a recording medium to required wavelengths each capable of forming a hole at absorption spectrum of the recording medium, synchronizes timing of change of the wavelength of the light source with timing of recording or regenerating each bit of information, records the optical hole formed in a manner that each bit of information corresponds to the wavelength varying in sequence, and detects the formed hole to regenerate information.