264 results about "Space modulation" patented technology

A light engine includes a multi-color laser source having a set of semiconductor lasers. A controller synchronizes the operation of the laser source to operate in a color sequential order with a spatial modulator.

An apparatus for wide-field functional imaging (WIFI) of tissue includes a spatially modulated reflectance/fluorescence imaging (SI) device capable of quantitative subsurface imaging across spatial scales, and a laser speckle imaging (LSI) device capable of quantitative subsurface imaging across spatial scales using integrated with the (SI) device. The SI device and LSI device are capable of independently providing quantitative measurement of tissue functional status.

The present invention relates to a method of measuring motion of an object such as a heart by magnetic resonance imaging. A pulse sequence is applied to spatially modulate a region of interest of the object and at least one first spectral peak is acquired from the Fourier domain of the spatially modulated object. The inverse Fourier transform information of the acquired first spectral-peaks is computed and a computed first harmonic phase image is determined from each spectral peak. The process is repeated to create a second harmonic phase image from each second spectral peak and the strain is determined from the first and second harmonic phase images. In a preferred embodiment, the method is employed to determine strain within the myocardium and to determine change in position of a point at two different times which may result in an increased distance or reduced distance. The method may be employed to determine the path of motion of a point through a sequence of tag images depicting movement of the heart. The method may be employed to determine circumferential strain and radial strain.

Methods and systems are provided for suppressing speckle and/or diffraction artifacts in coherent structured illumination sensing systems. A coherent radiation pattern forms an interference pattern at an illumination image plane and illuminates an object. Radiation scattered or otherwise emitted by the object is detected to produce a signal, which is integrated in time. Coherent artifact suppression is attained by using a spatial modulator, such as an acousto-optic device, to vary a phase gradient at the illumination image plane during the signal integration time. Various embodiments are provided for purposes including without limitation: preserving the depth of field of the coherent illumination; using the same acousto-optic device for pattern generation and coherent artifact suppression; electronically controlling the effective spatial coherence of the illumination system; and reducing errors due to coherent artifacts in a laser-based three dimensional imaging system.

An Orthogonal Time Frequency Space Modulation (OTFS) modulation scheme that maps data symbols, along with optional pilot symbols, using a symplectic-like transformation such as a 2D Fourier transform and optional scrambling operation, into a complex wave aggregate and be backward compatible with legacy OFDM systems, is described. This wave aggregate may be processed for transmission by selecting portions of the aggregate according to various time and frequency intervals. The output from this process can be used to modulate transmitted waveforms according to various time intervals over a plurality of narrow-band subcarriers, often by using mutually orthogonal subcarrier “tones” or carrier frequencies. The entire wave aggregate may be transmitted over various time intervals. At the receiver, an inverse of this process can be used to both characterize the data channel and to correct the received signals for channel distortions, thus receiving a clear form of the original data symbols.

A spatial light modulator includes an upper optically transmissive substrate held above a lower substrate containing addressing circuitry. One or more electrostatically deflectable elements are suspended by hinges from the upper substrate. In operation, individual mirrors are selectively deflected and serve to spatially modulate light that is incident to, and then reflected back through, the upper substrate. Motion stops may be attached to the reflective deflectable elements so that the mirror does not snap to the bottom substrate. Instead, the motion stop rests against the upper substrate thus limiting the deflection angle of the reflective deflectable elements.

A display is backlit by a source having spatially modulated luminance to attenuate illumination of dark areas of images and increase the dynamic range of the display.

A system for generating signals for Raman vibrational analysis, particularly for a CARS microscope or spectroscope of an external specimen, the system comprising a a laser source apt to emit at least one fundamental optical pulse in a first band of fundamental frequencies comprising at least one first (ω_f1) and one second (ω_f2) fundamental frequencies; a second-harmonic (SH) generating system comprising at least one nonlinear optical crystal for converting said at least one fundamental optical pulse into at least two second-harmonic optical pulses, i.e. a first second-harmonic pulse at a first second-harmonic frequency (ω_p) of the first fundamental frequency (ω_f1) and a second second-harmonic pulse at a second second-harmonic frequency (ω_s) of the second fundamental frequency (ω_f2), said second second-harmonic frequency being other than the first second-harmonic frequency, and a Raman vibrational analysis apparatus apt to receive said first and second second-harmonic pulses and direct them toward said specimen.

According to an embodiment, the SH system comprises two nonlinear optical crystals, each including a ferroelectric crystal with periodic space-modulation of the sign of the optical susceptibility.

In a different embodiment, the SH system comprises a ferroelectric crystal with aperiodic space-modulation of the sign of nonlinear optical susceptibility, with a period varying along the optical path of said at least one fundamental optical pulse, said crystal being apt to generate said first and second second-harmonic pulses.

A device for generating Orbital Angular Momentum (OAM) modes for radio communications. The device is designed to receive one or more input digital signals, each of which has a respective sampling period which is a respective multiple of a given sampling period, and occupies a frequency bandwidth which is a respective fraction of a given available frequency bandwidth. The device is operable to apply, to each input digital signal, a respective space modulation associated with a respective OAM mode having a respective topological charge to generate a corresponding digital signal carrying the respective OAM mode. The device is configured to apply, to each input digital signal, the respective space modulation by interpolating said input digital signal and phase-modulating the interpolated input digital signal so as to generate a corresponding phase-modulated digital signal carrying the respective OAM mode, having the given sampling period, and occupying the given available frequency bandwidth.

A method for determining a shear modulus of an elastic material with a known density value is provided. In this method, a spatially modulated acoustic radiation force is used to initially generate a disturbance of known spatial frequency or wavelength. The propagation of this initial displacement as a shear wave is measured using ultrasound tracking methods. A temporal frequency is determined based on the shear wave. The shear modulus of the elastic material at the point of excitation may be calculated using the values of the spatial wavelength, material density, and temporal frequency.

A free-space optical signal receiver includes a plurality of detectors whose individual outputs are delayed to correct for variations in arrival time caused by aberration in the medium through which the optical signal propagates, and combined to provide a single output. Each of the plurality of detectors sense the free-space modulated optical signal and provide a detector signal representative of the modulation of the optical signal. Each detector signal is delayed by a delay value to generate a delayed signal, and each delay value is selected to correct for variation in arrival time of the optical signal at each of the detectors, resulting in the delayed signals being substantially time-aligned. The delayed signals are constructively combined into a combined signal representative of the modulation aspect, and the combined signal is provided as an output.

The invention discloses a depth information acquiring device and method on the basis of a TOF technology and binocular vision. The device comprises an active light source emitting device, a TOF sensor, left and right image sensors, a controller and a processor, wherein the active light source emitting device comprises a light source, a space modulation device and an imaging system which are arranged successively; the active light source emitting device and the TOF sensor are connected with the controller; and the TOF sensor, the left image sensor and the right image sensor are connected with the processor. The active light source emitting device generates time and space modulated light illuminating scene, the TOF sensor acquires a time modulation signal to obtain depth information of the scene, and the left and right image sensors acquire a space modulation signal to obtain image information of the scene. Feather matching to the image of the scene is carried out according to the depth information which adds constraint condition so as to obtain a high-resolution depth image. High-resolution rapid depth information is acquired in indoor and outdoor environment at low cost, and the depth information acquiring device and method on the basis of the TOF technology and the binocular vision are suitable for short distance and long distance.

The invention discloses a naked eye 3D laser display device. The naked eye 3D laser display device comprises a directional projection screen, a laser light source, a red single-color laser light source, a green single-color laser light source and a blue single-color laser light source. Light rays emitted by the three single-color laser light sources at specific angles and specific positions are incident on the directional projection screen provided with nano grating pixels, the same outgoing light fields are formed, the laser light source provides multi-view-angle image pixels, the multi-view-angle image pixels match a nano grating pixel array on the directional projection screen, and, through direct space modulation for laser projection light, colorful 3D display is achieved; and crosstalk does not exist between various view point, and the naked eye 3D laser display device has the advantage that people has no watching visual fatigue, and has the advantage of low cost.

A method of performing a DFT (discrete Fourier transform) or a DFT derived transform on data, comprising: providing spatially modulated light having spatial coherence, said spatially modulated light representing the data to be transformed; Fourier transforming said spatially modulated light, using an at least one optical element; and compensating for at least one of a scaling effect and a dispersion effect of said at least one optical element, using an at least one dispersive optical element.

Exemplary embodiments are directed to a sound modification system and loud speaker system. The system may impose amplitude and frequency modulation on to a signal representing the output of an electrical musical instrument or other sound source while also imposing a sense of movement of the sound to the listener. Further, the system may simultaneously amplify sound signals without the amplitude, frequency and spatial sense of modulation or a different sense of modulation. The system combines a plurality of speaker transducers, a plurality of amplifiers and digital signal processors to provide a flexible, portable and practical sound modification and amplification system.

The invention provides a low complexity soft output space modulation detection method. The method comprises the following steps: firstly, for each possible transmitting antenna serial number l, mapping a received signal vector y to a channel vector hl direction to obtain a following formula; secondly, generating a quantitative formula according to constellation features and quantizing the following formula to obtain a most probable transmit symbol estimation, as the formula corresponding to each possible transmitting antenna index l; and thirdly, using the hl and the formula to calculate a metric value dl of each antenna-symbol pair, as the formula, so as to sort all antenna-symbol pairs, as the formula according to the dl, and select p antenna-symbol pairs therefrom, as the formula, with the smallest dl to calculate the bit log-likelihood ratio of the transmitting antenna serial number and the transmit symbol, so as to realize the soft output detection of space modulation in the form of log-likelihood ratio. The method reduces the antenna serial numbers and the number of symbols which need to be considered during bit log-likelihood ratio calculation, and greatly reduces the complexity of the detection algorithm of a receiving end of the space modulation technique. By selecting a small p value, the complexity of soft output detection can be further reduced on the basis of sacrificing little performance.

An optical processor adapted to emulate an artificial neural network (ANN) having a plurality of interconnected layers, each layer having one or more artificial neurons, the processor having a spatial light modulator (SLM) optically coupled, via an optical mask, to a photodetector array. In one embodiment, the SLM has a plurality of pixels, each pixel being configurable to emulate an output portion of a corresponding artificial neuron in a signal-sending ANN layer. The optical mask has a hologram that encodes the weights corresponding to interlayer connections in the ANN and spatially modulates the light transmitted by the SLM. The photodetectors of the array spatially resolve the interference pattern produced by the spatially modulated light, with each photodetector being configurable to emulate an input portion of a corresponding artificial neuron in a signal-receiving ANN layer.

For generating a plurality of light beams having different colors, time sequentially switching the light beams, illuminating a space modulation unit with the light beam, and projecting light modulated by and emitted from the space modulation unit, a white light illumination period is provided during a period between illumination periods for the plurality of light beams having different colors. An inexpensive and high quality image display apparatus is provided without using specific electronic circuits and space modulation unit and without using optical systems of high performance and large scale.

The invention relates to a laser system for the ionization of a sample by matrix-assisted laser desorption in mass spectrometric analysis. The invention consists in providing a laser system which generates a spatially modulated intensity distribution with intensity spots on the sample, which significantly improves the quality and the robustness of the mass spectrometric analysis compared with a spatially homogeneous intensity distribution and, in particular, improves the ionization efficiency and, for a time-of-flight mass spectrometer with axial injection, the mass resolution and the signal-to-noise ratio.

The invention discloses a laser repair device and a laser repair method, which can extremely precisely control irradiation of the laser beam and repair defect more appropriately. In the invention, a scheme storage part (123) stores irradiation condition image, and the irradiation condition image makes irradiation condition corresponding to a overlapping substance corresponds to each of a pluralityof overlapping areas on surface of a glass cardinal plate; a image processing part (127) that recognizes defect scope on surface of a FPD cardinal plate (101) manufactured through overlapping varioussubstance on the glass cardinal plate, and divides the defect scope as irradiation area according to irradiation condition image and which overlapping area is coincided; a master control part (122) that assigns more than one space modulation mode to a two dimensional space light modulator (106) by a laser control part (125) and a space modulation and control part (126) in series, so as to irradiate laser beam to the irradiation area according to irradiation condition of the irradiation area corresponding to overlapped area.