Abstract: A method for producing an intensity contrast image from phase detail in a transparent phase object also removes spurious background artifacts and speckle from the light source resulting in clearer images. A laser beam or other coherent light source is directed through the transparent phase object and focused into a photorefractive hologram recording crystal where a temporary volume phase hologram is formed. Once the hologram has formed a phase conjugate beam is created and passes back through the transparent phase object and is directed to an apparatus which records an intensity background pattern consisting of coherent artifacts. The transparent phase object is then mechanically shifted or allowed to move on its own in the case of transparent living specimens. The light source is directed through the physically translated transparent phase object and focused into the photorefractive hologram recording crystal.

Abstract: An optically implemented technique which generates the correlation function f two electrical signals. A reference signal is used in conjugation with an acousto-optic device to generate an optical field which is incident on a photorefractive crystal. This produces in the crystal a reflection phase conjugate wave front reconstructing volume hologram. A retropropagating reconstructed optical field passes back through the device which contains a second signal. This optical field is then focused onto a photodiode. The time varying component of the photodiode output is the correlation of the two signals.

Abstract: Apparatus and methods for producing an intensity image from a transparent phase object. A laser beam is generated and expanded. A shutter disposed in the path of the expanded laser beam is opened, and the expanded laser beam is split into first and second beams. The first beam is directed through the transparent phase object and focused into a photorefractive hologram recording crystal for the write time of the crystal. The shutter is closed, and the position of the transparent phase object is shifted an incremental amount. The shutter is opened again so that the first beam is directed through the shifted transparent phase object and into the photorefractive hologram recording crystal such that a phase-conjugate beam is produced traveling in the opposite direction of the first beam. The phase-conjugate beam is collimated, directed through the shifted transparent phase object, and split into third and fourth beams.

Abstract: A method for deforming materials which are ferroelectric, have remanent polarization, and which exhibit a length-dependent photoelectric effect. One type of material is photovoltaic, piezoelectric, ferroelectric ceramics. Illuminating such materials causes them to deform, either in length or in thickness, depending on the direction of the remanent polarization. A single plate of such material may be used, or a pair of plates bonded together may be used.

Abstract: Non-volatile semiconductor matrix random access and electrically alterable rogrammable read-only memories are disclosed. Each memory cell of the matrix memory includes a photovoltaic ferroelectric element which is remanently polarized with a write signal, and which when illuminated, produces a photovoltage which causes a field effect transistor to assume one of two states. Variable impedance means, for example, at least a diode or a breakdown diode is connected in each cell for providing a low impedance when the write gate pulse is applied to the photovoltaic ferroelectric element and for providing a high impedance when the photovoltage produced by the photovoltaic ferroelectric element is applied to the field effect transistor gate. If power to the memory is lost, by illuminating the photovoltaic ferroelectric element, the field effect transistor may be caused to assume the state which it was in before loss of power.

Abstract: A three dimensional memory which is comprised of a plurality of stacked memory planes, each of which includes at least a continuous transparent photovoltaic-ferroelectric layer sandwiched between two continuous plane transparent electrodes. In one embodiment, the memory planes are comprised of only the photovoltaic-ferroelectric layer sandwiched between the two electrodes, and in another embodiment the ferroelectric layer and a continuous transparent photoconductive layer are sandwiched between the two electrodes.

Abstract: A three dimensional memory having an increased storage capacity. The memory block has a matrix of cylindrical cavities, each of which has a fiber optic light guide means disposed therein. Each light guide means is comprised of a cylindrical core having a first index of refraction and a cladding surrounding the core having a second, smaller index of refraction; a plurality of spaced deformations are formed at the core-cladding interface for allowing light to leak out of the guide laterally.

Abstract: A photovoltaic cell comprised of a plurality of single crystal, remanently olarized, ferroelectric layers in a stack with electrodes affixed to each end. Additionally, electrodes are disposed between adjacent layers or conductive or semi-conductive regions are formed at and near the interfaces between layers by chemical reduction or doping. The cell has a higher conversion efficiency than ferroelectric cells heretofore known.

Abstract: An electrical battery comprised of a substrate of a radioactively ionized, electrically polarized, polycrystalline ferroelectric ceramic material, which is disposed between a pair of conductive electrodes. The radioactive ionization produces non-equilibrium carriers in the substrate, resulting in the development of an emf across the electrodes.

Abstract: A data recording and read-out apparatus and method in which a ferroelectric eramic substrate is remanently polarized to store information. Upon being illuminated, the substrate produces a photovoltaic voltage, which is detected to effect read-out. A disk of ferroelectric ceramic material to which information is entered by spiral tracking, either in a single track or in multiple tracks. A self-scanning data record comprised of a plurality of ferroelectric ceramic cells which are remanently polarized, and which are read out by a register.

Abstract: A method of transferring remanent polarization information from a photovoic ferroelectric unit to a polarizable unit which may either be another portion of the photovoltaic ferroelectric material or a separate piece of material. The photovoltaic ferroelectric unit is illuminated to produce a photovoltage and the voltage is applied to the unit to be polarized to induce the polarization. An optically addressable read-write photovoltaic ferroelectric memory plane having means for allowing writing and erasing of information by the transfer of remanent polarization from one portion of the memory plane to another.

Abstract: A high storage capacity, fast access time, photovoltaic ferroelectric mem apparatus including a plurality of memory planes which are stacked in a three dimensional configuration. Each plane is comprised of a photovoltaic ferroelectric layer and a photoconductive layer sandwiched between two electrodes. Writing of information is effected by illuminating a selected xy location on the planes while simultaneously applying a voltage pulse to a selected z plane, and reading is effected by illuminating a selected xy location while connecting a selected z plane to a read amplifier.

Abstract: A method and apparatus is disclosed by which high voltage and current can produced by a polycrystalline ferroelectric ceramic material in response to incident light. Numerous applications of the ferroelectric ceramic material taking advantage of such properties thereof are further disclosed. The polycrystalline ferroelectric ceramic material is initially poled by the application thereto of a pulse of voltage of predetermined magnitude and direction. After being poled in such fashion, the application of light impinging on the various surfaces of the ferroelectric ceramic material will induce a consistant high voltage between select surfaces of the ferroelectric ceramic material. Upon disposing electrodes in conductive contact with the material, a current can be generated to a load attached thereacross.

Abstract: An apparatus is disclosed which utilizes the high voltage generated by the mpingement of illumination upon a polarized polycrystalline ferroelectric ceramic material as the source of a high voltage electric field through which charged particles are accelerated. The application of such device to a D.C. particle accelerator with capabilities similar to accelerators of the Van de Graaf type is shown, a uniform DC electric field being provided not through linking resistors as is the case in the Van de Graaf machine, but rather directly through the intrinsic properties of the ferroelectric ceramic material, the uniformity and magnitude of such field being further improved in at least one preferred embodiment through the utilization of parallel spaced-apart electrodes disposed through the ferroelectric ceramic material and terminating in hoops or other electrodes creating equipotential planes through which a beam of charged particles is accelerated.