Rockwell International Corporation

California Institute of Technology

Rockwell Science Center, Inc.

Rockwell Technologies, Inc.

Caldera Micro Technology, Inc.

John H Hong

Demetri Psaltis

Pochi A Yeh

Scott E Fraser

Periklis Pantazis

Ye Pu

Youngwoo Kwon

Won Yup Ko

Zhiwen Liu

Frederick R Vachss

Tallis Y Chang

Kyushik Hong

Jinho Jeong

McMichael, Ian C

Nan-Lei Wang

Lance L Webb

Gregory J Steckman

John Hyunchul Hong

Theodore W Haensch

Martin Centurion

Nyuntae Kim

Second harmonic nanoprobes for imaging biological samples and a method of using such probes to monitor the dynamics of biological process using a field resonance enhanced second harmonic (FRESH) technique are provided. The second harmonic generating (SHG) nanoprobes are comprised of various kinds of nanocrystals that do not possess an inversion symmetry and therefore are capable of generating second harmonic signals that can then be detected by conventional two-photon microscopy for in vivo imaging of biological processes and structures such as cell signaling, neuroimaging, protein conformation probing, DNA conformation probing, gene transcription, virus infection and replication in cells, protein dynamics, tumor imaging and cancer therapy evaluation and diagnosis as well as quantification in optical imaging.

Second harmonic imaging nanoprobes and techniques for use thereof

Holographic methods for recording fast movies whose speed is limited by the laser pulse duration if the recording material has sufficient sensitivity to reliably record a frame of the fast event with a single pulse. The method we describe uses the selectivity of multiplexed holograms to resolve frames that are recorded with adjacent pulses. Specially designed pulse generators are used to generate the signal and reference pulse trains. We experimentally demonstrate the system by making movies of laser induced shock waves with a temporal resolution of 5.9 ns, limited by the pulse width of the Q-switched Nd:YAG laser used in the experiments.

Method and apparatus for holographic recording of fast phenomena

A variable bandwidth, distributed amplifier circuit includes an input transmission line; an output transmission line; and a plurality of amplifier cells having a respective plurality of cell inputs distributed along the input transmission line and cell outputs distributed along said output transmission line. Each amplifier cell comprises a cascode amplifier having an input transistor, an output transistor, and a variable impedance device in a circuit branch coupled to a gate of the output transistor. The impedance of the variable impedance device is responsive to a variable bias control signal.

Wideband, variable-bandwidth distributed amplifier

Acoustic wave characteristics varied by illumination of the acoustic wave propagation medium. An acoustic wave is generated and propagated on or through a medium, typically a piezoelectric substrate. The medium is illuminated, creating a charge grating. The velocity of the acoustic wave is altered and certain frequency components of the acoustic wave are reflected. Transducers may be used to extract the selected frequency. The characteristics of the illumination, including, among others, the wavelength and the intensity, may be varied to produce various acoustic wave velocities and to select particular acoustic wave frequency components.

Method and apparatus for modifying acoustic wave characteristics

A phased array antenna phase shifter having one or more serially connected stages, the stages allowing a transmission signal to pass through to a radiating element. Each of the stages have three or more delay lines for imparting a different respective delay on the transmission signal and a network of switches to select which of the delay lines within the stage will carry the transmission signal. As the signal is passed through each of the stages, the signal will experience the cumulative delays from the stages of the phase shifter. The delay lines in each stage comprise delay lines of different respective lengths, a delay is imparted on the transmission signal as it passed along the length of the selected delay line. The network of switches comprises micro electromechanical systems (MEMS) switches.

Base-3 switched-line phase shifter using micro electro mechanical (MEMS) technology

A phased array antenna system and method employs a phase delay network to provide a scan angle control signal to respective mixers, with phase delays that correspond to the lengths of delay lines between antenna elements. The mixers are connected in circuit with their respective antenna elements so that the scan angle is controlled by the frequency of the scan control signal, independent of the operating signal frequency for the antenna elements. The system can be tailored for either beam transmission or reception, and is applicable to both single and dual delay network versions as well as multi-dimensional arrays.

Electronically scanned phased array antenna system and method with scan control independent of radiating frequency

A method is provided for normalizing correlation data from a holographic correlator. After a sequence of object image patterns are recorded in an angularly multiplexed hologram, the entire volume hologram contents are read out with a uniform (plane wave) object beam. The plane wave readout produces an array of spots at a correlation plane, with the intensity of each spot representing the strength of the recorded hologram for the corresponding stored image pattern. The spot intensity values are accurately detected and stored as normalization factors. Holographic correlation output array values produced by parallel comparison of an input object pattern with the stored image patterns are then divided by the corresponding normalization factors. The resulting normalized correlation output accurately represents the true degree of correlation between the input object pattern and the stored image patterns by eliminating the uncertainty factor. The method generates accurate correlation values from a volume holographic correlator while maintaining high effective computational rates.

Normalization of data from holographic correlators

A method and apparatus are provided for reducing speckle noise in images read out from holographic memories. An image recorded in the memory is read out using a multiple component readout beam, with each component having the same horizontal orientation but a different vertical orientation. Because the Bragg effect is pronounced only in the horizontal direction, the readout beam components all access the same stored image. Each readout beam component is set to oscillate at a slightly different frequency such that the smallest frequency difference is greater than the reciprocal of the output detector response time. The multiple oscillating readout beam components can be produced by an acoustooptic deflector driven by a wideband electrical signal. The memory readout comprises multiple reconstructions of the desired image, with each image reconstruction oscillating at a slightly different optical frequency. The output detector receives a set of mutually incoherent image reconstructions that reduce the speckle noise through an image averaging effect, thereby improving the quality of the output image.

Holographic memory readout with reduced speckle

In a broad aspect the present invention comprises a multiple element, multi-throw electronic switch for a fiber optical cable network. The multiple element, multi-throw electronic switch includes a bulk media optical deflector angularly controllable by selectable electronic steering signals. At least one multiple element, multi-throw electronic switch is use to construct a true time delay shifter using rows of a plurality of columns of a plurality of beamsteering optical fiber delay lines, all with a specified antenna scanning coherence center. Distributed beamsteering is performed by selecting from the composite array, subarrays for which a common steering direction cosine can be applied to that subarray. The distributed beamforming is performed by combining elements beamsteered with a common antenna scanning coherence center from an electronically small core fibers with limited available modes into larger core multimode fibers. The distributed beamsteering and distributed beamforming is iterated until all antenna elements in the composite array have been beamsteered into an array with the identical specified antenna scanning coherence center. The bulk media optical deflector angularly controllable by selectable electronic steering signals has the additional advantage that a plurality of squint-free antenna beamsteering commands can be simultaneously implemented providing a frequency-independent means of antenna beam shaping which necessary for a frequency-independent monopulse processing capability.

Multi-element true time delay shifter for microwave beamsteering and

An apparatus and method are provided for transmitting two-dimensional images through a single mode optical fiber. Light from a broadband source is dispersed into component wavelengths, spatially modulated to contain an image, collected for multiplexing in a single mode optical transmission fiber, transmitted through the single mode fiber, and demultiplexed into its component wavelengths to reproduce the transmitted image. The two-dimensional dispersing and collecting elements may be realized using thin film channel waveguides having arrays of optical gratings. Because the dispersive element at the receiving (output) end of the transmission fiber must reproduce the dispersal pattern used at the source, the information transmitting device may be used for data encryption and decryption.

Wavelength multiplexed two dimensional image transmission through single

An electronic circuit is provided for comparing a plurality of input signals and indicating and/or selecting the maximum or minimum signal from the input set. The plurality of input signals are amplified, logarithmically compressed, and buffered by a corresponding plurality of simple transistor circuits, which are substantially identical. The buffered input signals are provided to a high resolution multiple input comparator circuit. The comparator circuit comprises a two-stage emitter-coupled comparator and a single stage inverter-amplifier. In the first comparator stage, strong input signals share the bias current but all the weak signals drop out. The inverter-amplifier stage amplifies the differences between the strong signals that survive the first comparison stage. The second stage comparator determines the strongest of the few remaining signals. With fewer competing signals, and enlarged voltage differences between them, the second stage comparator can determine the strongest of the original input signals with a high degree of resolution.

Analog maximum/minimum selector circuit

Holographic apparatus and methods are provided for generating high resolution telescopic images using low cost, small aperture lenses. Holographic media, such as photorefractive crystals, are used in conjunction with multiple and/or synthetic aperture techniques. In a multiple aperture system, a thin nonlinear holographic medium is used with a plurality of small optical lenses to compensate for the inherent piston and tilt errors of the lenses, thereby providing higher resolution. In another embodiment, synthetic aperture techniques are accomplished by illuminating a far field object with coherent light, deriving a reference beam from the coherent light, and changing the position of the reference beam in accordance with a computational formula. A hologram is formed from a sequence of image exposures in the holographic media, each made at different positions with respect to the image. The sequence of exposures is combined and phased in the holographic media to synthesize a high resolution image normally achievable only with a relatively larger aperture.

Holographic techniques for generating high resolution telescopic images

A photorefractive device is provided for converting an image-bearing incoherent input beam to a high contrast coherent output beam the intensity of which varies as the square of the input intensity pattern. The device uses an incoherent image beam to write a holographic grating directly in a photorefractive medium. In one embodiment, a parallel, laterally displaced, telecentric system of lenses is used to split a quasi-monochromatic, incoherent image-bearing beam into two equal components. The two components are superimposed at the surface of the photorefractive medium to produce the hologram. In a second embodiment, the incoherent input beam is directed through a physically translating external grating to write the hologram in the photorefractive medium. The moving grating improves the diffraction efficiency of the hologram under the influence of an applied electric field and stabilizes the temporal response characteristics for signal processing. In both embodiments, the photorefractive medium is exposed to a coherent beam that picks up the image from the hologram and produces a coherent output beam having a high contrast replica of the input image.

Photorefractive square law converter

A method is provided for reconstructing an image transmitted through a thick distorting medium. A remote source provides coherent light at the object plane, and a local source, typically derived from the remote source, provides corresponding light that is coherent with respect to the remote source. Light from the remote source is directed through the thick aberrator and into a holographic medium, such as a photorefractive crystal, to interact with corresponding light from the local source and produce a volume hologram. An angularly multiplexed volume hologram, which covers the entire object field, is written into the holographic medium by successive exposures of light from the remote and local sources for successive pixels of the object plane. Light from an object, which comprises two-dimensional information from the object plane, can be reconstructed by the volume hologram after being distorted by the thick aberrator. Light from each point of the object accesses the set of gratings in the volume hologram and reconstructs only the reference wave associated with it. Reconstructed waves emerging from the hologram are then focused by a following lens to form a high resolution image of the object at the image plane of the lens.

Growing community of inventors

Moorpark, CA, United States of America

John H Hong