Abstract: Methods for making a nonlinear optical device and related devices are dissed. The method includes creating an ordered dispersion of charged particles in a surrounding medium. The charged particles and the surrounding medium are chosen such that they initially have identical refractive indices. In accordance with one aspect of the invention, cadmium sulfide inclusions are added to at least one of (a) the particles or (b) the medium. The cadmium sulfide inclusions have a highly nonlinear refractive index. The inclusions are optically nonlinear and upon high intensity radiation the refractive index of the particles change. This change in the refractive index occurs on the order of nanoseconds. In accordance with another aspect of the invention, a nonfluorescent dye is incorporated into at least one of (a) the particles or (b) the medium. The dye is photoabsorptive. Upon being impinged with high intensity radiation, the dye absorbs photons and heats the surrounding particles.

Abstract: A modulating optical operation element is composed of a light receiving separation element having a pair of light receiving elements, a photoelectric operation element made of an operation element for calculating electric signals outputted from the light receiving separation element and outputting an electric signal in response to a result of this calculation, a transmission type light modulation element made of a transmission type liquid crystal sandwiched between transparent electrodes, and polarizers disposed on both sides of this light modulation element. An optical neuron yet for outputting an information beam consisting of light outputted from each optical neuron element is constituted by arranging a plurality of these elements a two-dimensional pattern.

Abstract: In an optical operation apparatus for carrying out an operation for finding an inner product of a first vector and a second vector by utilizing light, an optical vector encoding system forms an encoded distribution, which is based on all of elements of the first and second vectors, in which the intensities have been encoded in accordance with the values of the elements of the first vector, and in which the centers of gravity of local intensities have been position encoded in accordance with the values of the elements of the second vector. A product sum decoding system extracts a value of an inner product of the first vector and the second vector in accordance with the encoded distribution having been formed by the optical vector encoding system, and feeds out the information representing the inner product value.

Abstract: Photoresponse from a ferroelectric optical computing device, such as a memory cell or a logic switch, is increased by either illuminating the regions of the ferroelectric crystal under the electrode edges in a sandwich structure device or by aligning the principal axis of the ferroelectric crystal parallel to the linear polarization vector of the optical beam. Device density is increased by reducing the beam size using a small near-field optical fiber. Device evaluation including imprint failure susceptibility is performed by illuminating each ferroelectric optical computing device in a large array of such devices and storing the device address of any device whose response departs from a normal range.

Abstract: An optical digital holding apparatus of the present invention carries out functions of a flip-flop apparatus (RS flip-flop, D flip-flop etc.) which are one kind of electrical digital holding apparatus, and can be achieved by placing optical connecting wiring having a direct or indirect feedback circuit between multistage optical selectors having selector functions. The optical digital holding apparatus of the present invention includes multistage selectors which receive an aggregation of spatially distributed optical digital information signals propagating in a predetermined direction and bearing binary digital information and an optical control signal bearing binary digital information. These selectors selectively output a portion of an aggregation of the digital information signals received in accordance with a value of the digital information carried by the optical control signal.

Abstract: A laser beam modulation apparatus modulates a EFM (eight-fourteen modulated) signal to generate as a laser power control signal a pulse modulated EFM signal (PM-EFM). During each of on-time intervals of the EFM signal, the pulse modulated EFM signal serves to apply the laser beam on a recording area on a phase-change disk and to undulate the laser beam in order to prevent an overheating of the recording area.

Abstract: A modulator apparatus for modulating arrays of input data V.sub.in to be stored in a holographic recording medium is disclosed wherein the final output data array V.sub.out has frequent transitions from light to dark and from dark to light in either dimension across the data page and has the total amount of illuminated regions throughout the entire data page held constant. These two constraints are achieved by a first set of control arrays obtained from two fixed sets of m.times.n binary arrays {A.sub.0, A.sub.1, . . . , A.sub.n } and {B.sub.0, B.sub.1, . . . , B.sub.m } which in turn are obtained from fixed sets of binary control vectors {a.sub.0, a.sub.0, a.sub.1, . . . , a.sub.n }, {b.sub.0, b.sub.1, . . . , b.sub.m }, respectively. The control vectors a.sub.0, a.sub.1, . . . , a.sub.n any n+1 fixed elements of the inverse mapping, .phi. .sup.1 (C.sub.1), of the (t-2) error-correcting code C.sub.1 of length m. The control vectors b.sub.0, b.sub.1, . . . , b.sub.

Abstract: The object of the present invention is to control the amplification rate of a photoperiodic circuit by stable negative feedback control, thereby suppressing fluctuations in the circulating light in the photoperiodic circuit. The circulating light in the photoperiodic circuit is converted into an electrical signal, indicating the intensity of the circulating light, which is held in a first sample-and-hold circuit. Additionally, an electrical signal indicating the intensity of circulating light of the circuit previous to that of the first sample-and-hold circuit is held in a second sample-and-hold circuit. The difference in the value between the electrical signals which indicate intensities of the circulating light are determined by a subtraction circuit. The result is supplied to an addition circuit through a third sample-and-hold circuit.

Abstract: Optical communication systems, optical computing systems and optical logic elements which rely on the phenomina of cross-phase modulation to alter and control, either or simultaneously, the spectral, temporal or/and spatial properties of ultrashort light pulses for processing information with high speed repetition rates. A weak beam of ultrashort light pulses is modulated by an intense beam of ultrashort light pulses by copropagating both beams through a non-linear medium such that cross-phase modulation effects are realized.

Abstract: A new type of fully-multiplexed imaging device is described for use at wavelengths where efficient focal plane array detectors are unavailable. It shares some properties in common with the familiar technique of cycle-redundancy (i.e. Hadamard transform) imaging, but many of its features and capabilities are unique. Some of these characteristics are, first, the new approach employs image encoding masks that are both transmitting and reflecting, thereby increasing optical efficiency, and second, the technique requires only 2.sqroot.N encoding masks to image a field of N pixels, a dramatically smaller number than that needed (.about.2N) by traditional methods. Dual complementary inputs are used for first-order passive rejection of radiation background interference. The resulting image spatial resolutions along two coordinate directions are completely independent of each other. The measured image is formed by a convergent tiling of the image plane, quite unlike conventional raster scanning.

Abstract: An optical code recognition unit (OCRU) for recognising a predetermined n-bit optical code sequence coded using the Manchester code format, has an n-way splitter (7) having an input and n parallel outputs (7a). A plurality of gates (9a, 9b, 9c, 9d) are associated with the splitter outputs (7a), respective pairs of splitter outputs leading to each of the gates ( 9a, 9b, 9c) via a respective optical combiner (8a, 8b, 8c), and any remaining single splitter output leading directly to its gate (9d). Each of the splitter outputs (7a) is subject to a different delay of m half bit periods, where m=0 to 2(n-1), the values of m being chosen such that, if a predetermined optical code sequence is applied to the splitter input, the `1`s in the outputs of each of the pairs of splitter outputs (7a) reach the associated AND gates (9a, 9b, 9c) and the `1` in any remaining single splitter output (7a) reaches its AND gate (9d) at predetermined times such that all the gates are turned on.

Abstract: An optical processor includes a non-linear ring resonator with lasers and two waveguides with electrodes positioned above them. This optical processor extends its functional range, i.e. providing multi-level processing of optical signals, an increase of power responsivity of input signals, increasing the number of optical contacts. In this optical processor, semiconductor lasers have been provided on the coupling waveguides. Optical mode mixers in coupling regions have been generated by connecting the waveguides and the ring resonator in coupling regions so that the following relationship is observed: an one-mode waveguide and a ring resonator make up a two-mode mixer, and electrodes are applied above the coupling regions.

Abstract: Operation results for all combinations of input optical signal values to be operated are previously determined and substantially parallel light beams reflecting the operation results for all combinations are generated. Selectors for selecting transmission area of the input light beams in accordance with digital information born by optical signals are arranged for the respective optical signals along the direction of propagation of the light beams. Through the logically cascade-connected selectors, an optical signal corresponding to a combination of current input optical signals is selected from the operation results for all combinations.

Abstract: An architecture for an optical computing apparatus which utilizes global free space smart optical interconnects and is based on a digital logic family derived from augmenting semiconductor technology with optical logic. The apparatus comprises input means, control means, and detector means, where the detector means includes means for detecting an optical input signal, electronically amplifying and selectively negating the detected signal, and providing an optical output signal. The architecture is capable of providing outputs which are Boolean logical AND/OR operations on designated combinations of binary input bits, and in another embodiment is capable of forming the combinatorial functionals and summations into which an arbitrary user instruction may be decomposed by means of Shannon's theorem and DeMorgan's laws.

Abstract: A method of clocking integrated circuit chips. A pulsed laser striking an integrated circuit module substrate is diffused through the substrate and exits the opposite surface as diffused light pulses. An integrated circuit chip mounted on the top surface of the substrate has optical receivers. The optical receivers receive pulsed energy from the diffused light pulses, converting pulsed light to electrical pulses that clock the chip.

Abstract: Optical logic gates are designed using inverse-scattering theory, resulting in devices which are intrinsic and passive, having high extinction ratios and large fan out. The Boolean operation is modeled by a pair of reflection coefficients, corresponding to the `1` and `0` states of the device. When inverse scattering theory is applied, each reflection coefficient yields a unique refractive index profile. The multivalued nature of the refractive index profile is achieved by introducing nonlinearity in the core region of a thin-film waveguide, which acts as the basic structure of the devices.

Abstract: An optical system of an optical neural network model for parallel data processing is disclosed. Taking advantage of the fact that an auto-correlation matrix is symmetric with respect to a main diagonal and the weights for modulating the values of diagonals of the auto-correlation matrix are equal to each other, the configuration of an optical modulation unit is simplified by a one-dimensional modulation array on the one hand, and both positive and negative weights are capable of being computed at the same time on the other hand. In particular, the optical system makes up a second-order neural network exhibiting invariant characteristics against the translation and scale.

Abstract: An optical information processor for use as a matrix vector multiplier comprises a vector input spatial light modulator (1) and an optically addressed weight matrix spatial light modulator (3). A read beam (10) passes through the input modulator (1) and the weight modulator and onto a combined output transducer and error spatial light modulator (5). The error modulator (5) is then controlled in accordance with the difference between a target output vector and the output vector from the transducer (5), and modulates an update beam (11) which then passes through the input modulator (1) and onto the weight modulator (3). The weight modulator (3) represents a two-dimensional array of optical attenuation values which are updated in accordance with the optical radiation incident thereon during updating.

Abstract: Methods of and apparatus for manipulating beamed electromagnetic phenomenon comprises a generator (20) of aligned conical or pyramidal elements (21a-21f) each having conical or pyramidal inner and outer surfaces (24a-24f and 23a-23f). When the beamed electromagnetic phenomenon includes a zero-order component the elements (21a-21f) minimize or eliminate the zero-order component allowing for devices such as on-axis holographic displays, demodulators and optical processors for computers.

Abstract: An optical calculating apparatus which can perform operations by optically controlling incident light and hence perform such operations very rapidly and in parallel is provided. A unit component is composed of a pair of electrodes and a modulation material layer sandwiched therebetween and consisting of a material such as a liquid crystal in which the molecular struture is twisted by an applied electric field to change the transmission amount and transmission direction of light incident from the outside, thereby performing a modulation. The optical calculating apparatus is constructed by stacking or laminating such unit components in n stages. The unit component of the first stage has a structure in which the modulation material layer is sandwiched between a pair of the electrodes and input light enters into the modulation material layer in the direction perpendicular to the arrangement direction of the electrodes.

Abstract: An optical switching device for switching linearly polarized optical signal beams includes a plurality of switching cells arranged in matrix form. Each switching cell has spatial light modulators and a polarizing beamsplitter which cooperate to propagate the optical beams received by the device to selected output ports. The device can be three-dimensionally expanded to increase the number of output ports to which the optical beams can be selectively switched, in which case the matrices can share integrally constructed polarizing beamsplitters and SLMs.

Abstract: An optical logic element is disclosed which performs an XOR operation through utilization of the high-speed property of light. On each branched waveguide of a Mach-Zehnder interference type optical waveguide there is provided a phase modulating element whose refractive index undergoes a change when it is irradiated by light. The interference type optical waveguide is adapted to provide different optical output levels when the refractive index changes of the phase modulating elements are both zero or a predetermined value and when they differ from each other. Thus, the optical logic element is capable of performing the XOR or XNOR operation at an ultrahigh speed.

Abstract: An architecture for an optical computing apparatus which utilizes global free space smart optical interconnects and is based on a digital logic family derived from augmenting semiconductor technology with optical logic. The apparatus comprises input means, control means, and detector means, where the detector means includes means for detecting an optical input signal, electronically amplifying and selectively negating the detected signal, and providing an optical output signal. The architecture is capable of providing outputs which are Boolean logical AND/OR operations on designated combinations of binary input bits, and in another embodiment is capable of forming the combinatorial functionals and summations into which an arbitrary user instruction may be decomposed by means of Shannon's theorem and DeMorgan's laws.

Abstract: Amplification and synchronization of photon pulses in optical computing chips is accomplished by placing parametric amplifying devices at predetermined spatial locations in the light conductive paths that make up the optical circuits in the chip. The laser pumping signal for the parametric amplifiers is clocked by a system clock which also clocks the generation of the data photon pulses in the optical circuits. By synchronizing the arrival of a pumping pulse with the arrival of the photon pulse at a parametric amplifier, the data pulse can be amplified, reshaped and resynchronized. The pumping pulse can be directed to the spatially located parametric amplifiers on the chip in a number of different ways. The chip could be masked except for the parametric amplifiers, and the entire chip could be illuminated by the pumping laser though collimating lens. If the chip is not masked, then pumping light must be directed only to the parametric amplifiers.

Abstract: An exemplary packet processing apparatus where a large number of comparisons can be made concurrently in bit-parallel fashion by partitioning the comparison functionality to two optoelectronic integrated circuits, and interconnecting the two circuits using free space optics. Illustratively, different embodiments are used to perform one-to-many or many-to-one comparisons by developing multiple copies of one value for concurrent comparison with many possible values. The invention is more generally applicable to other comparison applications where one-to-many or many-to-one comparisons are made.

Abstract: Two-dimensional optical data is transferred at a variable rate through an tical delay module formed by spatial light modulators of the ferroelectric liquid crystal type interconnected in series for data transmission by a beam splitter through which laser radiation is introduced. Operation of the light modulators is controllably interrelated to control the variable delayed transfer rate of the module.

Abstract: A reconfigurable digital optical lookup table for solving Boolean equations sing an array of bistable optical devices is provided. A single light source is divided into a matrix of light beams using binary phase gratings and a lens system. This matrix of beams is modulated by a spatial light modulator symmetric self electro-optic effect device (S-SEED) according to the desired lookup table. The modulated light beams are used to set an S-SEED array with the lookup table. The rows and columns of the S-SEED array are then reset according to the inputs to the Boolean equation. Once all of the inputs have been processed, the S-SEED array will have only one member whose state has not been affected by the inputs, and the value of this S-SEED corresponds to the solution to the Boolean equation. The final result is output by using a matrix of equal intensity light beams and a mask to read out the state of one side of the S-SEEDs, and focusing the result onto a detector.

Abstract: An organic optical logic device comprising, as a nonlinear optical medium, a crystal of organic molecules which are excited to a state of electronic excitation with an oscillator strength of at least 1.0 by visible or near-infrared radiation within a region of wavelengths of 0.4 to 1.3 .mu.m operates at room temperature with a low energy at great speed when the electronic excitation of the crystal generates excitons or exciton polaritons having a resonance wavelength of .lambda..sub.0 and the organic optical logic device is operated with a driving light having a wavelength of .lambda..sub.o -50 nm to .lambda..sub.o +50 nm.

Abstract: An all-optical circulating shift register encodes a received optical clock signal with a value derived from an encoded optical signal received at a control port thereof. A data input to the shift register is used to modify an encoded optical signal. The resulting encoded clock signal, appearing at an output port, is coupled back to the control port. The shift register uses the encoded clock signal at the control port to encode a subsequently-received clock signal. In one embodiment, the optical shift register is implemented using a Sagnac switch having a feedback path coupled between an output port and a control port of the Sagnac switch.

Abstract: An analog optical processor for performing affine transformations and constructing fractal objects. An optical processor for optically performing an iterated affine transformation includes a rotating prism, an imaging lens and a translatable mirror, together with a pulsed laser as an input light source and an image detector array to record the final transformed image. The amount of rotation is determined by the setting of the rotating prism. The imaging lens provides the required magnification or demagnification. The translating mirror is shifted to provide the necessary translation. The pulsed image passes through the optical loop many times to perform the transformation. An optical Iterated Function System is implemented by connecting a plurality of the optical loops in parallel, together with shutters or beamsplitters for guiding the pulsed image to different loops according to the probabilities assigned by the Iterated Function System.

Abstract: An optical system is provided for the transformation of input images to be correlated by a pattern recognition system. A pulse of light from a laser carries an input image to a beam splitter. The beam splitter divides the input pulse into an output pulse and a thoughput pulse that is directed through an optical ring resonator. The ring resonator is an optical reimaging system that transforms the input image in scale or orientation. The transformed version of the input image is then directed to the beam splitter where it is split into a modified output pulse and a modified throughput pulse that reenters the ring resonator. The transformation process is self-repeating to generate a series of successively modified output images that are equally spaced in time. The series of output images can be provided to an optical pattern recognition system for correlation with a stored reference.

Abstract: An optical system for auto-associative and hetero-associative recall utilizing Hamming distance as the similarity measure between a binary input image vector V.sup.(k) and a binary image vector V.sup.(m) in a first memory array using an optical Exclusive-OR gate for multiplication of each of a plurality of different binary image vectors in memory by the input image vector. After integrating the light of each product V.sup.(k) .times.V.sup.(m), a shortest Hamming distance detection electronics module determines which product has the lowest light intensity and emits a signal that activates a light emitting diode to illuminate a corresponding image vector in a second memory array for display. That corresponding image vector is identical to the memory image vector V.sup.(m) in the first memory array for auto-associative recall or related to it, such as by name, for hetero-associative recall.

Abstract: A neural network processing element uses primarily optical components to model a biological neuron having both spatial and temporal dependence. The neural network processing element includes a switch-controlled laser source, a multiple holographic lens, a spatial/temporal light modulator, and a photodetector array. Laser beam control may be optical, electrical or acoustical, or a combination of these.

Abstract: In a photoelectronic interconnection device, N.times.N light emitting elements are arranged on a light emitting plane in a matrix pattern and N.times.N light sensing elements are arranged on a light receiving plane in a matrix pattern corresponding to the light emitting elements. A lens array of p.times.p optical lenses is provided, the lenses being disposed on a common optical plane located so that it is spaced from the light receiving plane at a distance q times greater than its distance to the light emitting plane, where N=pq, the lenses being spaced apart from each other at pitch (pq+1)a/(q+1), and a is a pitch between successive light emitting elements.

Abstract: For inputting a two-dimensional image into an optical neural network apparatus, a primary processing device is used to extract the characteristic feature of an object pattern. Thereafter, compressed information as a result of the above processing is inputted into the input of the all-optical type optical neural network apparatus, that implements parallel processings adaptively through optical computing, at individual points on the input of the same. Therefore, the primary processing device that was capable of dealing with only logical input information until now can process even vague input information by the use of the optical neural network apparatus located on the later stage.

Abstract: An electro-optical system that implements the self-tiling process of fining proper Iterated Function Systems for modeling natural objects. The system can operate in two different modes, a real-time interactive mode and an automated mode. The purpose of the system is to speed up the process of finding a proper IFS for a given object to be modeled. The system makes use of optical processing, including optical means for rotating, magnifying/demagnifying and translating an input image. Optical beamsplitters are used to combine transformed images to produce a tiled output image. In one embodiment, an automated controller evaluates the goodness of the match between the tiled image and the input image and generates control signals which cause adjustment of the settings of the optical means. The process is repeated automatically until the match is sufficiently good. The invention can also be operated in a manual, man-in-the-loop mode.

Abstract: In an image correlation calculation apparatus for optically calculating correlations between reference patterns and an image such as a character or any other figure, the image such as the character or any other figure subjected to correlation calculations is optically multiplied by a multiplier to form simultaneously in parallel a plurality of optical pattern images of a substantially identical shape, and optical correlation calculation between the plurality of optical pattern images and the reference patterns formed on various types of reference masks is performed individually and instantaneously, the various type of reference masks being arranged at a position spaced apart by a predetermined distance from the plurality of optical pattern image, thereby detecting beams emitted through the various types of reference masks.

Abstract: A multiple-faced optical device comprising a light-responsive element having multiple faces, at least two of the faces constituting input faces for receipt of non-collinear light signals and at least one of the faces other than the input faces constituting an output face from which light signals transmitted through the light-responsive element are emitted. The light-responsive element is further configured to have optically-induced non-linear susceptibility to light signals transversely propagated through the light-responsive element such that at least one portion of the light-responsive element switches between two stable optical states in dependence on the total intensity of the light signals within the light-responsive element. The above-described optical device can be configured to perform various operations, such as AND/OR and INVERT/PASS logic operations, data line branching, signal time delay, and memory storage.