Abstract: A coherent wideband acousto-optic RF spectrum analyzer for processing an input RF signal, having a CW laser providing a first laser beam, a Bragg cell used in a deflection mode with the laser beam incident thereon and receiving the input RF signal, and in response thereto producing multiple diffracted modulated light beams, a Fourier Transform lens with the modulated light beams incident thereon and in response thereto producing optical signal beams producing a Fourier Transform image in an image plane spaced apart from the Fourier Transform lens, and a photosensitive, optically re-writable medium positioned in the image plane with the optical signal beams incident thereon, the medium having an optical distribution pattern to function as a mask to attenuate a selected portion of the RF spectrum of the optical signal beams and produce an attenuated optical beam.

Abstract: An optical communications system is disclosed. In the optical communications system, a received light source is modulated in accordance with an electrical signal using an acousto-optic modulator. The acousto-optic modulator modulates an amplitude of the received light source in accordance with an amplitude of the electrical signal. Furthermore, an angle of diffraction of a beam produced by the acousto-optic modulator is a function of a frequency of the electrical signal. The optical communications system is equipped with a waveplate that converts a polarization of the diffracted beam to correspond to the polarization of an undiffracted beam. Improved detection and recovery of the electrical signal may be achieved due to the polarization correspondence between the diffracted beam and the undiffracted beam.

Abstract: A coherent wideband acousto-optic RF spectrum analyzer for processing an input RF signal, having a CW laser providing a first laser beam, a Bragg cell used in a deflection mode with the laser beam incident thereon and receiving the input RF signal, and in response thereto producing multiple diffracted modulated light beams, a Fourier Transform lens with the modulated light beams incident thereon and in response thereto producing optical signal beams producing a Fourier Transform image in an image plane spaced apart from the Fourier Transform lens, and a photosensitive, optically re-writable medium positioned in the image plane with the optical signal beams incident thereon, the medium having an optical distribution pattern to function as a mask to attenuate a selected portion of the RF spectrum of the optical signal beams and produce an attenuated optical beam.

Abstract: An optical communications system is disclosed. In the optical communications system, a received light source is modulated in accordance with an electrical signal using an acousto-optic modulator. The acousto-optic modulator modulates an amplitude of the received light source in accordance with an amplitude of the electrical signal. Furthermore, an angle of diffraction of a beam produced by the acousto-optic modulator is a function of a frequency of the electrical signal. The optical communications system is equipped with a waveplate that converts a polarization of the diffracted beam to correspond to the polarization of an undiffracted beam. Improved detection and recovery of the electrical signal may be achieved due to the polarization correspondence between the diffracted beam and the undiffracted beam.

Abstract: A method for improving uptake of contrast agents, such as manganese-based contrast agents, is neuronal imaging of areas such as the spinal cord and cortical spinal tract with magnetic resonance imaging are provided. Electrical stimulation is applied to the subject in order to increase uptake of the contrast agent in to the neuron, resulting in an improved image.

Abstract: The present invention provides methods for determining brain functioning in an individual by measuring the amount of either N-acetylaspartate or choline in an individual's brain. The present invention also provides methods for determining a change in an individual's brain functioning due to a change in the concentration of N-acetylaspartate or choline in the individual's brain.

Abstract: The present invention provides a method for determining whether an individual has a central nervous system disease or injury comprising: obtaining a T2 measurement for at least one brain tissue sample from an individual; determining if the T2 measurement indicates the presence of a central nervous system disease or injury in the individual. The present invention also provides a method for determining whether an individual has a central nervous system disease or injury comprising: obtaining a first T2 measurement using an MRI technique for a brain tissue sample from an individual at a first time; obtaining a second T2 measurement using an MRI technique for the brain tissue sample from the individual at a second time; and comparing the second T2 measurement to the first T2 measurement.

Abstract: An optical communication system for communicating information. The systems includes a source of continuous wave laser light and one or more acoustic beams whcih are frequency or amplitude modulated by data. The laser light beam and the acoustic beams are input to an acousto-optical modulator for producing an undiffracted laser light beam and one or more diffracted laser light beams. The diffracted laser light beams are frequently shifted from the undiffracted laser light beam and contain the data to be transmitted. The diffracted and undiffracted beams are combined and transmitted over an optical fiber for demodulation at a distant location by a receiver. The receiver includes a photodiode which heterodynes the diffracted and undiffracted beams and produces signals having the frequencies of the acoustic beams. Tuning circuitry separates the signals and demodulators reconstruct the data transmitted.

Abstract: A method for volume-selected NMR spectroscopy where an rf pulse of selected bandwidth, in the presence of a field gradient superimposed upon an initial homogenous magnetic field, rotates a slice of magnetization into the transverse plane, and it then uses a high power refocussing pulse to refocus the phase roll that accompanies the rf pulse. After an appropriate time, the magnetization is pulsed back to the homogenous magnetic field axis and the gradient collapsed. A read pulse is used to tip the magnetization of interest into the transverse plane for acquisition in the absence of applied gradients.

Abstract: An optical memory system for storage and retrieval of digital data using a source of writing light in the visible light range and a separate source of near infrared, polarized reading light. The writing light is amplitude modulated by a signal containing the digital data to be stored. Horizontal and vertical deflectors deflect the beams to scan horizontally and vertically in response to control signals. The scanning beams are focused to a focal point to impinge upon a stationary medium manufactured of a dry film having submicron electrically photosensitive particles embedded in a thermoplastic layer mounted on a substantially transparent electrically conductive substrate. The particles are insensitive to light at the reading light wavelength. The particles are initially uncharged and the film is sensitive to light after receiving an initial surface charge.