摘要:
A system and method for directional sound sensing directs an optical sensing beam to an object of interest having a rough surface that vibrates acoustically. The light is reflected thereby and scattered as a speckle pattern that includes multiple speckles having a random distribution of phase offsets. A detector array having multiple detector elements receives and detects the speckle pattern and produces signals that are linearly proportional to phase modulation of the speckles. A summer receives signals from at least two of the detector elements that are offset at different phases and sums the received signals to generate a non-vanishing signal representative of an acoustic signal.
摘要:
A device for bending a laser beam is provided. The device includes a beam deflection device that produces the beam having a selected number of addressable points. A soliton forming mechanism is positioned at the output of the beam deflection device so it receives the beam and increases the number of addressable points by a certain magnitude.
摘要:
A method and system are presented for reconstructing an input field where the latter is sensed by a measurement system. The method comprises: providing measured data corresponding to output field of said measurement system; providing data about sparsity of the input field, and data about effective response function of the measurement system; and processing the measured data based on said known data, the processing comprising: determining a sparse vector as a function of said measured data, said data about the sparsity of the input field, and said data about the effective response function; and using the sparse vector for reconstructing the input information. The invention allows for sub-wavelength resolution in imaging applications, and allows for detection of very short pulses by slow detectors in some other applications.
摘要:
An optical pin-point microphone has a light source for directing a sensing beam to an object of interest so as to be reflected thereby as a reflected signal beam, a detector having multiple detector elements for receiving the reflected signal beam, and a summer for receiving signals from at least two of the detector elements and detecting, rectifying, amplifying and summing the received signals to generate a non-vanishing signal representative of an acoustic signal.
摘要:
An apparatus, system and method for providing an image enhancing effect for a photographic image of a target region within an intravascular environment. The image enhancing effects may be a physical process based upon the nature of the detected light or based upon different aspects of expected light reflection behavior, for example, by running predefined image reconstruction algorithms. The apparatus has a plurality of different embodiments, each of which reduces the ambient “noise” detected along with the light reflected from the target region in order to increase the signal/noise ratio, thereby to enhance the quality of the image produced.
摘要:
An apparatus, system and method for providing a photographic image of a target region within an intravascular environment. The apparatus has a plurality of different embodiments, each of which reduces the ambient “noise” detected along with the light reflected from the target region in order to increase the signal/noise ratio, thereby to enhance the quality of the image produced.
摘要:
New methods are presented for multiplexing volume holograms in electrooptic materials. Multiple volume holograms can be superimposed in a medium and be individually addressed by tuning the underlying refractive index of the medium or the crystal parameters, while keeping the external parameters (wavelength, angles) fixed. According to the presented methods, the refractive index and crystal parameters of the material can be varied via the electrooptic, elastooptic or piezoelectric effects, alone or in combination with each other, by tuning the value of an applied electric field, or by tuning an applied mechanical stress, or by changing the material temperature. Volume holograms that have been multiplexed by either wavelength or angle or electric field or mechanical stress or temperature can be individually addressed by any one of the same five parameters. Additionally, selective, updatable fixing and erasing of volume holograms in photorefractive media is described. Each holographic page may be fixed individually and overwritten without destroying the other fixed pages. Further, Second Harmonic Generation and Parametric Amplification by optically induced periodic poling in ferroelectric photorefractive materials is described.
摘要:
A method and system are presented for reconstructing an input field where the latter is sensed by a measurement system. The method comprises: providing measured data corresponding to output field of said measurement system; providing data about sparsity of the input field, and data about effective response function of the measurement system; and processing the measured data based on said known data, the processing comprising: determining a sparse vector as a function of said measured data, said data about the sparsity of the input field, and said data about the effective response function; and using the sparse vector for reconstructing the input information. The invention allows for sub-wavelength resolution in imaging applications, and allows for detection of very short pulses by slow detectors in some other applications.
摘要:
A system for manipulating a fluid medium is disclosed. The system comprises a plurality of particles suspended in the fluid medium, and a light source configured for irradiating the particles by light to induce nonlinear optical effects. The particles are constituted such that the nonlinear optical effects result in drag forces exerted by the particles on the fluid medium. The magnitude of the drag forces is sufficient to establish hydrodynamic flow of the fluid medium.
摘要:
An apparatus for all-optical deflection of an incident optical signal beam, the apparatus comprising: a photorefractive semiconductor crystal; and an electric field source, for applying an electric field across the crystal either through electrodes or by positioning the crystal at a place where an electric field is present. In another embodiment of the invention a second optical beam source, for illuminating the crystal with a background optical beam. The apparatus is used for steering the signal beam, lensing it or for other applications.