Abstract: A ferroelectric device includes a first electrode and a second electrode that each comprise one or more electrically conductive layers. The ferroelectric device also includes a layer of ferroelectric material disposed between, and in electrical communication with, the first electrode and the second electrode. The first electrode and/or the second electrode include a recessed region and the layer of ferroelectric material includes a corresponding region of increased thickness that resists polarity changes. For example, a programming signal that is applied across the first and second electrodes may change a polarity of one or more other portions of the layer of ferroelectric material without changing a polarity of a portion of the layer of ferroelectric material that is proximate to the region of increased thickness. A corresponding method is also disclosed herein.

Abstract: A memory device is provided. The memory device includes a memory array; a first circuit electrically connected to the memory array, and causing the memory array to be operated in a first mode; and a second circuit electrically connected to the memory array, and causing the memory array to be operated in a second mode.

Abstract: A method for conserving power in a device. The method generally includes the steps of (A) generating a polarity signal by analyzing a current one of a plurality of data items having a plurality of data bits, the polarity signal having an inversion bit indicating that the current data item is to be stored in one of (i) an inverted condition and (ii) a non-inverted condition relative to a normal condition such that a majority of the data bits have a first logic state, wherein reading one of the data bits having the first logic state consumes less power than reading one of the data bits having a second logic state, (B) selectively either (i) inverting the current data item or (ii) not inverting current the data item based on the inversion bit and (C) storing the current data item in a plurality of single-ended bit cells in the device.

Abstract: The invention relates to proton-translocating retinal proteins which exhibit a photocycle which is retarded as compared with the wild type and whose all-trans retinal contents in the light-adapted and dark-adapted states do not differ from each other by more than 10%. The invention furthermore relates to a photochromic composition and to the use of the proton-translocating retinal proteins and the photochromic composition.

Abstract: A word line voltage is applied to a plurality of word lines. A read/write voltage is applied to a plurality of bit lines. The read/write voltage is applied to a plurality of source lines. A word line selector selects the word line and applies the word line voltage. A driver applies a predetermined voltage to the bit line and the source line, thereby supplying a current to the memory cell. A read circuit reads a first current having flowed through the memory cell, and determines data stored in the memory cell. When performing the read, the driver supplies a second current to second bit lines among other bit lines, which are adjacent to the first bit line through which the first current has flowed. The second current generates a magnetic field in a direction to suppress a write error in the memory cell from which data is to be read.

Abstract: The write disturb that occurs in polymer memories may be reduced by writing back data after a read in a fashion which offsets any effect on the polarity of bits in bit lines associated with the addressed bit. For example, each time the data is written back, its polarity may be alternately changed. In another embodiment, the polarity may be randomly changed.

Abstract: A ferroelectric nanostructure formed as a low dimensional nano-scale ferroelectric material having at least one vortex ring of polarization generating an ordered toroid moment switchable between multi-stable states. A stress-free ferroelectric nanodot under open-circuit-like electrical boundary conditions maintains such a vortex structure for their local dipoles when subject to a transverse inhomogeneous static electric field controlling the direction of the macroscopic toroidal moment. Stress is also capable of controlling the vortex's chirality, because of the electromechanical coupling that exists in ferroelectric nanodots.

Abstract: A method for conserving power in a device is disclosed. The method generally includes the steps of (A) storing a plurality of data items in a plurality of bit cells in the device such that a majority of the bit cells holding the data items have a first logic state, wherein reading one of the bit cells having the first logic state consumes less power than reading one of the bit cells having a second logic state; (B) generating a polarity signal by analyzing the data items, the polarity signal indicating that the data items are stored in one of (i) an inverted condition and (ii) a non-inverted condition relative to a normal condition; and (C) driving at least one of the data items onto an external interface of the device in the normal condition during a read operation based on the polarity signal.

Abstract: A phase-change random access memory device is provided. The phase-change random access memory device includes a plurality of memory blocks, a main word line, a plurality of local word lines and a plurality of section word line drivers connected between the main word line and each of the plurality of local word lines and adapted to adjusting voltage levels of the plurality of local word lines in response of voltages applied to the main word line and block information. The plurality of section word line drivers include at least one first section word line driver and at least one second section word line driver. The first section word line drivers include pull-down devices while not including pull-up devices.

Abstract: A non-volatile memory cell includes a switch able resistor memory element in series with a switch device. An array of such cells may be programmed using only positive voltages. A method for programming such cells also supports a direct write of both 0 and 1 data states without requirement of a block erase operation, and is scaleable for use with relatively low voltage power supplies. A method for reading such cells reduces read disturb of a selected memory cell by impressing a read bias voltage having a polarity opposite that of a set voltage employed to change the switch able resistor memory element to a low resistance state. Such programming and read methods are well suited for use in a three-dimensional memory array formed on multiple levels above a substrate, particularly those having extremely compact array line drivers on very tight layout pitch.

Abstract: A heat sink assembly is provided to afford cooling for electronic components mounted on a circuit board. The assembly consists of a thermal conducting substrate base with a top and bottom side. Radiating fins are attached to the bottom side of the base. The fins are cooled by external air. The component on the circuit board is connected to the top surface of the heat sink base by means of thermal conducting spacers which create a gap between the bottom surface of the circuit board and the top surface of the heat sink base. A first hole is placed in the heat sink base and driving means are attached to the said base at the area of the first hole. A rotating fan is operatively attached to the said driving means in such a manner that when the fan rotates air is forced between the gap created between the circuit board and the heat sink base. A second hole is installed in the heat sink base. The air flowing from the fan is exhausted through the said second hole.

Abstract: An optical recording medium, an optical recording and reproducing method, and an apparatus that can record and reproduce multilevel information at a high density and with a high S/N ratio. Recording light emitted from a light source is collimated by a collimation lens and introduced into a polarization rotary device. Recording light transmitted by the polarization rotary device is focused by an objective lens onto an optical recording medium. In response, a photo-induced birefringence is recorded on the optical recording medium. Multilevel recording is performed by controlling a voltage applied to the polarization rotary device to change a polarization angle ? of recording light. Reproduction is performed by detecting light reflected from the optical recording medium with an analyzer and a detector.

Abstract: The write disturb that occurs in polymer memories may be reduced by writing back data after a read in a fashion which offsets any effect on the polarity of bits in bit lines associated with the addressed bit. For example, each time the data is written back, its polarity may be alternately changed. In another embodiment, the polarity may be randomly changed.

Abstract: A system for writing data to and reading data from a magnetic semiconductor memory utilizing a spin polarized electron beam. The magnetic semiconductor memory comprises a plurality of storage locations, each storage location includes a magnetic material and a layer of semiconductor material capable of emitting photons. The method of reading data from the magnetic semiconductor memory comprising steps of directing a spin-polarized electron beam at the magnetic semiconductor memory, and detecting the light emission state of the semiconductor layer from the magnetic semiconductor memory.

Abstract: Ferroelectric memory includes a hollow formed in a first insulation film. A lower electrode is formed in this hollow by sol-gel method including an application process due to a spin coat method. In this application process, a precursor solution is dripped on a surface of the first insulation film and splashed away due to centrifugal force. Due to this, a first conductive film to being formed has an increased film thickness at portion of the hollow where the precursor solution is ready to correct, or portion to be formed into a lower electrode, and a decreased film thickness at portion other than the hollow. Accordingly, it is satisfactory to etch only the hollow portion when forming a lower electrode by dry-etching the first conductive film.

Abstract: A method of erasable/rewritable optical data storage is provided in which a laser beam from a laser (10) operated in either a pulsed or continuous wave mode is focussed by an optical system (11-18) onto a photorefractive polymeric material (32) to cause two photon excitation of the material to record data which may subsequently be erased by illuminating the material with radiation having a wavelength in the ultraviolet or visible spectrum to erase the recorded data. New photorefractive polymeric materials having a relatively narrow absorption band for use in the method are also disclosed.

Abstract: A write line structure for a magnetic memory cell includes a write conductor having a front surface facing the memory cell, a back surface and two sides surfaces. A cladding layer is disposed adjacent a portion of the front surface of the write conductor, with the cladding layer terminating at spaced first and second poles adjacent the front surface of the write conductor. A data storage layer is operatively positioned adjacent the cladding layer. The distance between the poles is less than the width of the write conductor. The width of the data storage layer may be greater than or less than the distance between the poles.

Abstract: A write line structure for a magnetic memory cell includes a write conductor having a front surface facing the memory cell, a back surface and two sides surfaces. A cladding layer is disposed adjacent a portion of the front surface of the write conductor, with the cladding layer terminating at spaced first and second poles adjacent the front surface of the write conductor. A data storage layer is operatively positioned adjacent the cladding layer. The distance between the poles is less than the width of the write conductor. The width of the data storage layer may be greater than or less than the distance between the poles.

Abstract: A method and apparatus for performing read and write operations in matrix-addressed memory array of memory cells is described. The memory cells comprising an electrically polarizable material exhibiting polarization remanence, in particular and electret or ferroelectric material, where a logical value stored in a memory cell is represented by an actual polarization state in the memory cell. The degree of polarization in the polarizable material is limited during each read and write cycle to a value defined by a circuit device controlling the read and write operations, with said value ranging from zero to an upper limit corresponding to saturation of the polarization and consistent with predetermined criterta for a reliable detection of a logic state of a memory cell.

Abstract: A system for storing data on a magnetic medium using spin polarized electron beams is provided. The system includes a source of spin polarized electrons and a storage medium disposed a selected distance from the source. The storage medium has a plurality of storage locations, each of which includes a layer of magnetic material sandwiched between first and second layers of a half-metallic material. The resulting sandwich structure forms a spin dependent electron trap that increases coupling between beam electrons in a first spin state and target electrons in a second spin state. An electron optics system directs the source of spin polarized electrons to one of the plurality of storage locations.

Abstract: A data storage device including a substrate, a data storage layer on the substrate, and a spin-polarized electron source. The data storage layer comprises a fixed number of atomic layers of a magnetic material which provide the data storage layer with a magnetic anisotropy perpendicular to a surface of the data storage layer. A data magnetic field is created in the data storage layer. The data magnetic field is polarized either in a first direction corresponding to a first data value or in a second direction corresponding to a second data value.

Abstract: Compositions of bacteriorhodopsin variants with increased memory time and their use for reversible optical information recording are disclosed. The compositions are characterized in that the configuration of the retinal of the photoproduct is different from the configuration of the retinal of the initial state and other than 13-cis; the pH value of the composition lies between 3 and 11; the water content of the composition lies between 1 and 30% by weight with respect to the total weight of the composition; and additives for modulating the proton mobility are present in a concentration between 1 and 80% by weight of the mass of purple membrane composition used, and if required matrix materials in a concentration of up to 10% by weight with respect to the total weight of the composition are present. These compositions may be used in reversible information recording systems.

Abstract: An object of the present invention is to provide a ferroelectric storage device which has long life in use. A switch-signal generating portion 40 automatically generates switch signals in predetermined timing. A reversal-of-polarity controlling portion 36 changes, on the switch signal, the polarity states of ferroelectric storage cells composing an information storage portion 30. After that the reversal-of-polarity controlling portion 36 further performs a certain number of write operations or read-out operations on said ferroelectric storage cell so as to further move the polarity state in the direction of the changed polarity. A gate controlling portion 38 gives a control-of-input-gate signal and a control-of-output-gate signal to an input gate portion 32 and an output gate portion 34, thereby changing states of their operations. Therefore, the polarity state can be changed if required with the same data being stored in the ferroelectric storage cell.

Abstract: A data storage device including a substrate, a data storage layer on the substrate, and a spin-polarized electron source. The data storage layer comprises a fixed number of atomic layers of a magnetic material which provide the data storage layer with a magnetic anisotropy perpendicular to a surface of the data storage layer. A data magnetic field is created in the data storage layer. The data magnetic field is polarized either in a first direction corresponding to a first data value or in a second direction corresponding to a second data value.

Abstract: A method and circuit for sensing multi states of a NAND memory cell by applying plurality of external sensing bias current at a constant positive gate and bias voltage and detecting a cell current wherein the cell current depends upon the state of the memory cell.

Abstract: A system for storing data on a magnetic medium using spin polarized electron beams is provided. The system includes a source of spin polarized electrons and a storage medium disposed a selected distance from the source. The storage medium has a plurality of storage locations, each of which includes a layer of a first non-magnetic material, a layer of magnetic material deposited on the first non-magnetic material, and layer of a second non-magnetic material deposited on the magnetic material. The second material is included to scatter spin polarized electrons from the source into an interaction volume of the magnetic material. An electron optics system directs the source of spin polarized electrons to one of the plurality of storage locations.

Abstract: An apparatus and method for electro-optically controlling the path of a laser beam or other electromagnetic beam in a suitable spectrum (e.g. visible, infrared, etc.) operates entirely in a solid state. Crystalline carbon-60 is manufactured in a gaseous environment to produce carbon-60 balls, each capturing a polarized molecule or ion susceptible to application of an electric field. Carbon-60 balls are suspended in a matrix of transparent gel, cured polymer, or held by their own solid, crystalline structure. Electrodes for controlling electric fields imposed upon the head, preferably shaped as a semi-spherical object, may be energized by alternating voltage to provide an alternating field. The ions or polarized molecules may oscillate within the carbon-60 "cages" in any direction as dictated by multiple, phased, field electrodes.

Abstract: A nonvolatile memory system is described. The system includes ferroelectric memory cells each comprising a pair of metal plates and a ferroelectric material therebetween. Data are stored in the cells by applying an electric field corresponding to the desired data value across a given cell, thereby setting the polarity of the ferroelectric material to a given state. A datum is read from a cell by a mechanical force to the ferroelectric material and sensing charge induced on one of the cells.

Abstract: It is an object of the present invention to provide a ferroelectric memory device having a high integration and capable of maintaining nonvolatility. A threshold voltage V.sub.th of a ferroelectric memory element is set at value slightly higher than a voltage -V.sub.1. A voltage 0V is applied as a gate voltage V.sub.G when the stored data is read out. A voltage V.sub.1 is generated at a MOS capacitor C.sub.MOS if the data "High" is stored and the voltage -V.sub.1 is generated at the MOS capacitor C.sub.MOS if the data "Low" is stored. The stored data is read out by detecting a drain current during generation of the voltages. Also, a voltage 0V is applied as the gate voltage V.sub.G when stand-by operation is carried out. In this way, variation of the gate voltage V.sub.G caused by switching ON and OFF of a power source can be prevented. So that, nonvolatility of the ferroelectric memory device can be maintained as a result of preventing spontaneous polarization of a ferroelectric capacitor C.sub.ferro.

Abstract: A ultra-high density memory device utilizing a photoinductive ferromagnetic thin film. A photoinductive ferromagnetic thin film is formed on a GaAs substrate, and a tip is arranged so as to face the photoinductive ferromagnetic thin film. The GaAs substrate is disposed on an xyz scanner, and the three-dimensional positional relationship between the GaAs substrate and the tip is changed by the xyz scanner. Blue light is radiated onto the thin film in order to make the magnetization orientation of molecules uniform. Through application of a relatively high voltage, a relatively large current is caused to flow between the tip and the substrate, so that randomization of the magnetization orientation of molecules of the photoinductive ferromagnetic thin film; i.e., writing operation is carried out.

Abstract: The invention relates to systems and methods for optical Fourier processing and logic operations based on the discovery that the photoinduced anisotropy of photochromic materials such as bacteriorhodopsin, organic fulgides, azo and fluorescent dyes, phycobiliproteins, rhodopsins, and their analogs, is dependent on the intensity of a polarized actinic beam that illuminates the material and the intensity profile of one or more input beams. This intensity dependence can be used to implement a simple, real-time, self-adaptive optical processing, i.e., spatial filtering, system for Fourier processing of optical input images. This optical processing system can be used to process a wide variety of optical input images, from projected still images to live motion picture images.

Abstract: Spin polarized apparatus includes a spin polarizing section of magnetic material with an electron input port and a polarized electron port and a transport section of magnetic material with a polarized electron input port electrically coupled to the polarized electron port of the polarizing section and an electron output port. Electrons traversing the polarizing section all have similar spin directions at the output dependent upon the magnetization direction of the polarizing section. Electrons traversing the transport section all have spins in a first direction at the output. The cell has a low resistance when the magnetization direction of the polarizing section is in the first direction (electrons entering the transport section all have spins in the first direction) and a high resistance when the magnetization direction is in an opposite direction (electrons entering the transport section all have spins in the opposite direction).

Abstract: Scanning head including a magneto-optical element and scanning device including the scanning head. A scanning head having a head face (1) comprises flux-guiding elements (3a, 3b) and a magneto-optical element (5). The magneto-optical element is disposed in a gap plane (4) which extends between flux-guiding elements.

Abstract: A data storage medium comprising a substrate and a data storage layer formed on the substrate. The data storage layer comprises a fixed number of atomic layers of a magnetic material which provide the data storage layer with a magnetic anisotropy perpendicular to a surface of the data storage layer. A data magnetic field is created in the data storage layer. The data magnetic field is polarized either in a first direction corresponding to a first data value or in a second direction corresponding to a second data value. Data is stored in the data storage layer by providing a spin-polarized electron having an electron magnetic field with a direction of polarization corresponding to one of the first and the second data values, and directing the spin-polarized electron at the data magnetic field to impart the direction of polarization of the electron magnetic field to the data magnetic field.

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: A data storage device including a substrate, a data storage layer on the substrate, and a spin-polarized electron source. The data storage layer comprises a fixed number of atomic layers of a magnetic material which provide the data storage layer with a magnetic anisotropy perpendicular to a surface of the data storage layer. A data magnetic field is created in the data storage layer. The data magnetic field is polarized either in a first direction corresponding to a first data value or in a second direction corresponding to a second data value.

Abstract: A data storage medium comprising a substrate and a data storage layer formed on the substrate. The data storage layer comprises a fixed number of atomic layers of a magnetic material which provide the data storage layer with a magnetic anisotropy perpendicular to a surface of the data storage layer. A data magnetic field is created in the data storage layer. The data magnetic field is polarized either in a first direction corresponding to a first data value or in a second direction corresponding to a second data value. Data is stored in the data storage layer by providing a spin-polarized electron having an electron magnetic field with a direction of polarization corresponding to one of the first and the second data values, and directing the spin-polarized electron at the data magnetic field to impart the direction of polarization of the electron magnetic field to the data magnetic field.

Abstract: An optical storage medium including a transparent polymer and an isomerizable AZO dye, the optical storage medium being coated as a water miscible solution on a substrate so as to form a film having a thickness of from .mu.m to 100 .mu.m storing information through birefringence and having a diffraction efficiency greater than 40% at a 1 millisecond response time. The isomerizable AZO dye remains in the film and is present in a concentration of from 4.5% to 25% based on the weight of the film.

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: A recording medium comprises a recording layer, a birefringent layer, and a reflecting layer. The recording layer is formed of a material whose optical rotatory power is alterable such that in one state no optical rotatory power is present and, in a second state, optical rotatory power is present. Information is recorded in the recording layer by selectively altering the state of the recording layer. The birefringent layer is formed of a material having constant birefringence without regard to the state of the recording layer. The reflecting layer reflects a light beam transmitted through the recording layer and the birefringent layer to reintroduce the beam into the birefringent layer and the recording layer. A method of reproducing information from this recording medium applies a polarized light beam to the recording medium and detects change of the polarized state of the polarized light beam reflected from the recording medium, thereby reading the information recorded in the recording layer.

Abstract: This application concerns an optical storage with an optical storage medium having a plurality of storage fields arranged in matrix fashion, wherein each storage field of this storage field matrix comprises a storage position matrix consisting of a number of storage positions arranged in matrix fashion, and an X/Y deflection system for random-addressing a storage position of a storage field of the storage field matrix responsive to an X- and a Y-control signal generated by a control unit, so that a light beam impinging on the X/Y deflection system is directed to a storage position of a storage field of the optical storage medium corresponding to the position of the X/Y deflection system.

Abstract: A data storage system is described which includes a magnetostrictive, anisotropic, ferromagnetic film whose domains exhibit a preferred orientation and are initially poled in one direction along the preferred orientation. A field is applied in opposition to the one direction, the field being insufficient to cause a switching of the poled domains. An electrostrictive film is placed in contact with the ferromagnetic film and a writing system is provided to actuate the electrostrictive film to impart stresses to the ferromagnetic film at selected locations. The induced stresses reduce the anisotropy energy of the ferromagnetic film at the selected locations and enable the domains thereat to become poled in accordance with the applied field. In one version of the invention, the writing means comprises a directed energy beam such as a laser or electron beam. In another version, the writing system employs surface acoustic waves in combination with a scanned energy beam.

Abstract: An associative data processor including a spin glass type amorphous magnetic film has input areas, output areas, and "hidden" or associative areas. A coil provides selective magnetic biasing, and lasers provide selective digital input to the input and output areas, which are intercoupled by the associative areas. Following input of a number of digital patterns to the processor, and "learning" by heating the associative areas, an incomplete input pattern may be applied, and the complete pattern read by sensing the polarization of reflected polarized light from the output areas.

Abstract: An opto-magnetic signal reproducing apparatus includes a light source unit for applying a linearly polarized light beam to a recording medium having magnetically recorded information, a splitter for splitting the light beam modulated, responding to the recorded information by a magneto-optic effect, into two light beams having different polarization directions from each other, and a reproducing device for differentially detecting the split light beams to reproduce the recorded information. The splitter imparts a phase different equal to an integer multiple of .pi. to each of the split light beams.

Abstract: A method for bistable storage of binary optical information includes an antiferroelectric (AFE) lead lanthanum zirconate titanate (PLZT) layer having a stable antiferroelectric first phase and a ferroelectric (FE) second phase obtained by applying a switching electric field across the surface of the device. Optical information is stored by illuminating selected portions of the layer to photoactivate an FE to AFE transition in those portions. Erasure of the stored information is obtained by reapplying the switching field.

Abstract: A polymer and dye combination suitable for use in optically recording information. The present invention includes a material which may exhibit the property of birefringence under selected conditions such as when stretched. This birefringence can be relaxed in localized areas by heating the localized areas. Incorporated within the material is a dye. The dye is selected so that it has a high optical density, or absorption maximum, in a specific range. This range may cover, for example, the wavelength of a gallium arsenide laser. Radiation with a wavelength within the selected range is the directed into the material at selected locations. This radiation is converted to heat, which in turn relaxes the birefringence in the localized areas or may cause other physical or chemical changes within the polymer. The localized relaxation of birefringence or other change can then be detected or "read." This allows information to be optically recorded on the polymer and subsequently detected and used.

Abstract: Methods and compositions for use in optically recording information. The present invention includes incorporating solute molecules within an extremely viscous medium. The solute molecules may be chemically bound within the medium or they may be held physically in place. In either case actual rotation of the solute molecules is prevented. The solute molecules are chosen such that they are capable of generalized pseudorotation. That is, the solute molecules or chromophores attached to a polymer chain may be converted from a first form to a second form which differs in orientation without a net chemical transformation into another chemical species and in the absence of actual rotation. In addition, the various forms of the solute molecules can be produced by passing selectively polarized light through the medium. The form of the solute molecules can then be "read" by passing light through the medium and detecting its characteristics as it exits the medium.

Abstract: An electro-optic memory effect providing for storing, erasing and rewriting igital information relies upon a ferroelectric polymer, polyvinylidene fluoride. Recent development of tri-fluoroethylene copolymers of this material with Curie temperatures below the melting point provides a means of selective writing, storage and erasure. The advantage of the polyvinylidene fluoride material for optical recording is its high chemical and physical stability. This material provides a mechanism for bit-by-bit erasure and long time storage of information.

Abstract: In a magneto-optical file memory wherein a storage medium having a vertical magnetic film is irradiated with a laser beam to reverse a magnetization direction of the magnetic film, thereby to write and/or erase information, and a rotation of polarizable face of reflected light from the storage medium is detected, thereby to reproduce information; a magneto-optical file memory wherein a sense of a leakage magnetic field of an actuator which controls an optical system for condensing the laser beam on the storage medium is set to be the same as a sense of initial magnetization of the magnetic film of the storage medium.