41 results about "Degree of coherence" patented technology

A method of measuring the contents of a search volume. The method includes: energising one or more transmitters so as to transmit electromagnetic wave energy into the search volume; detecting the effect of the search volume on the passage of the electromagnetic wave energy by recording two or more signals, each signal being associated with a different propagation path (typically either a monostatic or bistatic path) within the search volume; aligning the signals in order to generate two or more aligned signals which are synthetically focused on a desired voxel in the search volume, each aligned signal being associated with a different propagation path (typically either a monostatic or bistatic path) within the search volume; calculating a quality factor by processing the aligned signals to generate two or more data values, and processing the data values to generate a quality factor, the quality factor being indicative of a degree of coherence in the aligned signals; summing the aligned signals to generate a summed signal; and processing the summed signal to generate an output which is indicative of the internal structure of the search volume at the location of the desired voxel, the output varying in accordance with the quality factor.

Method and system for measuring the degree of coherence of nodes in a hierarchy. A hierarchy that includes a plurality of nodes is received. A plurality of training cases are also received. Based on these inputs, a measure of coherence is determined for at least one node D in the hierarchy. The determination of the measure of coherence includes evaluation of the training cases with at least one feature under a local environment of node D and evaluation of the training cases with at least one feature under a subtree of the node D.

The invention relates to a device and a method for measuring ultrafine grains based on dynamic light scattering signal time coherence degree. An incidence light path consists of a laser, a convex lens and a sample cell; a receiving light path consists of a sample cell, a pinhole diaphragm and an optical filter; and an acquisition and processing unit for scattering signals consists of a photoelectric detector, a photon counting plate and a computer. The measuring method comprises the following steps: 1, using the laser as a light source to irradiate the sample cell filled with the grains; 2, using a photoelectric multiplier tube as the photoelectric detector to continuously measure scattered light signals generated by the grains at a scattering angle of 90 degrees; 3, using the photon counting plate to count impulse signals output by the photoelectric multiplier tube, wherein the time coherence degree of the signals is gradually reduced along with the improvement of a sampling cycle; and 4, calculating the grain sizes of the grains by the computer according to the change of the calculated signal time coherence degree. The device and the method have the advantages of low cost, simple steps, quick measuring speed, and simple device.

The invention discloses an initial space coherence self-adaptive control method and a system of atmospheric signal path communication laser, which belong to the technical field of atmospheric signal path wireless laser communication. The invention generates a two-dimensional random phase screen through the mean and variance data of signals sent from a communication terminal of the other party; the two-dimensional random phase screen serves as a control signal to control a liquid crystal space light modulator to add a random phase before the save of transmitted communication laser, so that the optimal control to the initial space coherence of the communication laser is realized. The invention can significantly reduce the impact of atmospheric turbulence on the wireless laser communication system, and improve the performance of the communication system.

An illumination system for a microlithography projection exposure apparatus is designed for illuminating an illumination field with an illumination radiation with a predeterminable degree of coherence σ, it being possible to adjust the degree of coherence within a degree of coherence range extending into the range of very small degrees of coherence of significantly less than σ=0.2. The illumination system may have a first optical system for generating a predeterminable light distribution in an entrance plane of a light mixing device, and also a light mixing device for homogenizing the impinging radiation. The first optical system and the light mixing device can in each case be changed over between a plurality of configurations corresponding to different degree of coherence ranges. The degree of coherence ranges overlap and are dimensioned such that the resulting total degree of coherence range is larger than the individual degree of coherence ranges.

A high-brightness pulsed electron source, which has the potential for many useful applications in electron microscopy, inverse photo-emission, low energy electron scattering experiments, and electron holography has been described. The source makes use of Cs atoms in an atomic beam. The source is cycled beginning with a laser pulse that excites a single Cs atom on average to a band of high-lying Rydberg nP states. The resulting valence electron Rydberg wave packet evolves in a nearly classical Kepler orbit. When the electron reaches apogee, an electric field pulse is applied that ionizes the atom and accelerates the electron away from its parent ion. The collection of electron wave packets thus generated in a series of cycles can occupy a phase volume near the quantum limit and it can possess very high brightness. Each wave packet can exhibit a considerable degree of coherence.

The invention discloses a remote reference magnetotelluric impedance calculation method based on correlation detection, and belongs to the field of geophysical exploration, for overcoming the disadvantage of low accuracy of conventional magnetotelluric tensor impedance calculation. The method comprises the following steps: electric fields and magnetic fields of a base station and a reference station are respectively acquired, processed and obtained, electromagnetic field coherence degrees of the base station and the reference station are respectively calculated, when the two electromagnetic field coherence degrees are greater than a certain threshold, data segments are reserved and marked, and data segments, free from non-relevant noise interference, of the base station and the reference station are obtained; and then, magnetic field component coherence degrees of the base station and the reference station with the marked data segments are calculated, when the magnetic field component coherence degrees are greater than a certain threshold, data segments, free from noise interference, of these magnetic fields are reserved, otherwise, the data segments are abandoned, participation in subsequent tensor impedance estimation is canceled, tensor impedance estimation is carried out by use of a conventional remote reference magnetotelluric mode based on a Robust method, and apparent resistivity and impedance phase values are calculated by use of tensor estimated values. The method provided by the invention is applied to magnetotelluric exploration.

This invention relates to magnetotelluric survey data signal processing technology. It is a magnetotelluric impedance measurement method. Step: the signal acquisition by the least square method magnetotelluric impedance, and consulate frequency of the electric field and magnetic field signal coherent signal, when more than 75 percent of coherent measurement frequency and impedance in the 0.7-1 phase in the rate of broadband not within the 175-180, magnetotelluric impedance calculation and the results recorded or graphical format. Otherwise, a robust method magnetotelluric impedance type of interference or under the time domain or frequency domain using wavelet automatic threshold pressure on the magnetotelluric method noise signal noise filtering pressure, the invention is conducive to raising magnetotelluric data accuracy and reliability to avoid the man-made factor of magnetotelluric impedance calculation of the impact and relevance of a single judge by MT data quality in near-field presence made an error.

A wavefront aberration measuring device includes a mask which arranges a group of minute apertures for generating a group of point light sources at an object point as a measurement objective of an inspection-objective optical system, an illumination system which illuminates the mask with an illumination light, a diffraction grating which shears, into a plurality of light fluxes, a light flux exiting from the group of minute apertures and passing via the inspection-objective optical system, and a detecting portion which detects an interference fringe formed mutually by the plurality of sheared light fluxes, wherein a center spacing distance L between adjacent minute apertures which are adjacent in a shear direction in the group of minute apertures is defined to minimize the coherence degree.

Metal sheet band to be measured is positioned between two Michelson interferometers. Two corresponding surfaces of metal sheet band to be measured are as a reflecting surface for each interferometer. The two Michelson interferometers are cascaded to form a differentiate interference system. A light source in low degree of coherence through first light transmission system irradiates onto first Michelson interferometers, from which output light through second light transmission system as a light source irradiates onto second interferometers. Opto-electronic receiver receives output light from the second interferometers through third transmission system. After signal processor carries out process, thickness of metal sheet band is obtained. Advantages are: high measuring sensitivity, and antivibration. The invention is suitable to opaque object with high reflectivity in both surfaces, and very thin sheet band with no substrate supported or with transparent substrate supported.

A wake vortex avoidance system includes a microphone array configured to detect low frequency sounds. A signal processor determines a geometric mean coherence based on the detected low frequency sounds. A display displays wake vortices based on the determined geometric mean coherence.

Disclosed is a novel system and method to select software components. A set of available software components are accessed. Next, one or more dimensions are defined. Each dimension is an attribute to the set of available software components. A set of coherence distances between each pair of the available software components in the set of available software components is calculated for each of the dimensions that have been defined. Each of the coherence distances are combined between each pair of the available software components that has been calculated in the set of the coherence distances into an overall coherence degree for each of the available software components. Using the overall coherence degree, one or more software components are selected to be included in a software bundle.

The invention discloses an artificial microstructure construction method and an optical system comprising an artificial microstructure. The method comprises the following steps: S10, determining the phase of to-be-generated partially coherent light at each cellular position of a corresponding artificial microstructure area according to the coherence of the to-be-generated partially coherent light;S20, calculating a rotation angle of the nano cells arranged at each cell position; S30, arranging the nano cells with different rotation angles at corresponding cell positions, and constructing theartificial microstructure for realizing light beam coherence regulation. According to the invention, a focused light beam is incident to the surface of the constructed artificial microstructure, and the incident area of the artificial microstructure is selected as required, so the partially coherent light beam with the corresponding coherence degree can be obtained.

The invention discloses a radar staring correlated imaging method based on target prior information. The method comprises the implementation process as follows: (1) constructing a radar emission arraysurface; (2) generating a radar frequency hopping signal; (3) generating a rotating imaging plane of each pulse in an emission signal; (4) calculating delay time of the emission signal correspondingto the rotating imaging plane of each pulse; (5) generating a space-time radiation field matrix; (6) solving a target scattering coefficient to obtain an image of a target in the rotating imaging plane. By use of prior information of the target, the defects of larger space coherence degree of condition number and normalization of space-time radiation fields in a traditional static imaging method and target imaging errors caused by Taylor approximation in a motion compensation method are overcome, and high-resolution imaging of the target in the rotating imaging plane by radar can be realized.

The invention discloses a method for determining the direction of a partially-coherent laguerre-gaussian light beam vortex. A partially-coherent laguerre-gaussian light beam which is to be measured is divided into reference light and pilot light through a spectroscope. The pilot light passes through two cylindrical surface lenses which are perpendicular to each other, and transmits for a distance z, and then asymmetric spatial distribution of pilot light intersecting spectral concentration of the pilot light is measured through an association system; the reference light goes through a light beam analysis system so as to measure light intensity spatial distribution of the light beam; the asymmetric spatial distribution of pilot light intersecting spectral concentration which is measured above and the light intensity spatial distribution of the reference light are subjected to computer processing according to first-order coherence degree vortex distribution characteristics of the laguerre-gaussian light beam to obtain a first-order coherence degree distribution map of the to-be-measured light beam. The deflection direction of a symmetric axis of the distribution map is corresponding to the direction of the partially-coherent laguerre-gaussian light beam vortex. The method provided by the invention for measuring the direction of the light beam coherent vortex does not require expensive apparatuses. The measurement apparatus is simple. The determination is visual. The result is reliable.

Disclosed is a novel system and method to select software components. A set of available software components are accessed. Next, one or more dimensions are defined. Each dimension is an attribute to the set of available software components. A set of coherence distances between each pair of the available software components in the set of available software components is calculated for each of the dimensions that have been defined. Each of the coherence distances are combined between each pair of the available software components that has been calculated in the set of the coherence distances into an overall coherence degree for each of the available software components. Using the overall coherence degree, one or more software components are selected to be included in a software bundle.

Disclosed is a novel system and method to select software components. A set of available software components are accessed. Next, one or more dimensions are defined. Each dimension is an attribute to the set of available software components. A set of coherence distances between each pair of the available software components in the set of available software components is calculated for each of the dimensions that have been defined. Each of the coherence distances are combined between each pair of the available software components that has been calculated in the set of the coherence distances into an overall coherence degree for each of the available software components. Using the overall coherence degree, one or more software components are selected to be included in a software bundle.

The invention provides a photonic crystal fiber. The fiber comprises a photonic crystal fiber taking selenium arsenide as a matrix material; a plurality of air holes are distributed in the cross section of the photonic crystal fiber; from the inside to the outside of the photonic crystal fiber, the air holes are arranged in a hexagonal shape and sequentially form a plurality of circles of air holes; the air holes in the innermost ring are filled with chalcogenide compounds. The invention also relates to a coherent mid-infrared super-continuum spectrum light source. The fiber is advantaged in that the high-coherence mid-infrared supercontinuum is generated in the near-zero flat full-positive dispersion chalcogenide glass photonic crystal fiber, a problem of low coherence of a current mid-infrared supercontinuum light source is solved. The coherent mid-infrared super-continuum spectrum light source is advantaged in that the structure is simple, the output spectrum covers the mid-infraredband, the coherence degree is high and the like, and the coherent mid-infrared super-continuum spectrum light source has immeasurable application prospects in the fields of optical coherence tomography, spectrum detection, nonlinear microscopes and the like.

The invention discloses a device for controlling a particle light leakage switch by using an associated vortex array. The method comprises the following implementation steps: preparing a group of hologram sequences by using a computer, loading the hologram sequences to a spatial light modulator, and repeatedly playing in a dynamic frame form; irradiating the spatial light modulator by using laser,and enabling a light beam to be vertically upward through reflection, that is, opposite to the direction of a gravity field; selecting first-order diffracted light of the reflected light beam and irradiating the first-order diffracted light into a 10x objective lens for focusing to form a light trap; putting the particles into an optical trap, wherein the state of the particles is determined by the phase and coherence degree of an associated vortex light beam generated by modulation of a spatial light modulator. Different hologram sequences are prepared by changing parameters and loaded to the spatial light modulator to be played in the form of a dynamic frame, so that control over up-down movement and rotation of particles is achieved. The device provided by the invention uses a small number of optical devices, is simple in layout, and belongs to the field of optical manipulation.

A system (100) for inducing a subject (110) to fall asleep comprises a monitor (120) for monitoring heart rate and breathing rate of the subject (110), a coherence assessing device (130) coupled to the monitor (120) for assessing a degree of coherence between the heart rate and the breathing rate, and an output device (140, 150) coupled to the coherence assessing device (130). The output device (140, 150) may comprise a light pattern generator (140) for generating a light pattern (145) in view of the subject (110) based on the degree of coherence. The output device (140, 150) may alternatively or additionally comprise an instructing system (150) for instructing the subject on a breathing pattern, and wherein the instructions are given based on the degree of coherence.

The invention discloses a flame simulation device comprising a casing (1) and the following components arranged in the casing (1): an analog hearth (2), at least one light source (3) of an imaging screen (6) and a transparent cylinder (4), wherein the light sources (3) of the imaging screen (6) are arranged at the back side of the casing (1), the transparent cylinder (4) is positioned above the light sources (3), liquid which can fluctuate is arranged in the transparent cylinder (4), the light sources (3) are laser beams, and the imaging screen (6) is unidirectional mirror glass which is semi-transparent. Compared with the prior art, the invention forms a dynamic flame simulation image with diversified size transformation and uninterrupted up-and-down leap on the imaging screen finally by light rays penetrating through the transparent cylinder through utilizing the characteristics of strong directivity, very high brightness, high degree of coherence, large energy density and the like of the laser beams and simulates flame as real flame, the simulated flame has a graceful effect, can jump, leap and twinkle randomly and has different positions and very strong stereoscopic impression, the brightness is also very good, and the combustion state is very lifelike.

The present invention relates to a masstone photomask and pattern transfer method using the same. The masstone photomask forms transfer pattern having a transparent zone, a light shading zone and a semi-transparent zone by using a photomask (23) arranged on a transparent substrate (21) to shade exposure light and a semi-transparent film (22) for the exposure light. An optical system with value hole diameter of 0.08 and degree of coherence of 0.8 receives exposure light with g ray, h ray and i ray of 1:1:1 through the semi-transparent zone and calculates effective transmission rate of the semi-transparent zone, herein mask surface internal distribution range of effective transmission rate of the semi-transparent zone is lower than 2.0%.

The invention discloses a sound mixing system and method capable of automatic distributing gains. The sound mixing system capable of automatic distributing gains comprises a collection module, a detection module and an order module; the collection module is connected to each sound pickup module and each power amplification module and is used for collecting a first audio frequency signal from each sound pickup module and collecting a second audio frequency signal outputted from the power amplification module; the detection module is connected to the collection module and is used for performing comparison detection on a degree of coherence of a first audio frequency signal and a second audio frequency signal which are collected at the same time in order to determine the coherence of the first audio frequency signal and the second audio frequency; the order module is connected to the detection module and is used for transmitting a gain distribution order according to a coherence result determined by the detection module in order to make the gain distribution module change an output gain of the audio frequency signal collected by each pickup module connected to the gain distribution module according to a gain distribution order. The sound mixing system and method capable of the automatic distributing gain can prevent mutual interference between audio frequency signals among multiple microphones in the sound mixing system, improves a voice output effect of the sound mixing system and enhances a voice output effect of the sound mixing system.

The layered generation of at least one volume grating in a recording medium by way of exposure, the recording medium having at least one photosensitive layer which is sensitized for a presettable wavelength of the exposure light. Each volume grating is generated in the recording medium by at least two wave fronts of coherent light capable of generating interference, the wave fronts being superposed in the recording medium at a presettable depth, at a presettable angle and with a presettable interference contrast. The depth and the thickness of the refractive index modulation and / or transparency modulation of a volume grating in the recording medium is controlled by depth-specific control of the spatial and / or temporal degree of coherence of the interfering wave fronts in the direction of light propagation.

The invention is suitable for the technical field of optical measurement, and provides a device, a method and a system for measuring the second-order coherence degree of light. The invention discloses a light second-order coherence degree measuring device, and the device comprises a laser output module which is used for outputting a plurality of laser beams; the thermo-optical modulation module is used for receiving the laser beam of the laser output module and converting the laser beam into thermo-optical; the single-photon modulation module is used for receiving the laser beam of the laser output module and converting the wavelength of the laser beam to obtain a single-photon beam; and the photon detection module is used for receiving the thermal light and the single-photon light beam and is used for coincidence measurement counting of the second-order coherence degree of the thermal light and the second-order coherence degree of the single-photon light beam. The thermo-optical modulation module and the single-photon modulation module are arranged in the same optical path, so that the second-order coherence degree of different optical fields can be measured at the same time, and the experiment effect is richer.

A technique for generating good system decompositions is disclosed. The illustrative embodiment uses evolutionary programming in combination with a fitness function to generate a system decomposition that has a low degree of coupling and a high degree of coherence. A system is represented by an object-oriented specification using the Unified Modeling Language (UML); the UML specification is then represented by an eXtended Markup Language (XML) document, and the contents of the document are transformed into a nested-list data structure that resembles source code in a functional programming language such as Common LISP. The nested-list data structure and an appropriate fitness function are input to an evolutionary programming engine that operates on the nested-list data structure as though it were a source code program, and generates an output source code program. A system decomposition is then derived from the output source code program.

The invention provides a method for calculating the temperature, pressure and dryness of the injected steam and nitrogen mixture. The outlet is the initial calculation point, and the step size can be set arbitrarily to calculate the wellhead temperature, wellhead pressure and wellhead dryness distribution at the wellhead of the surface pipeline; the wellhead is the initial calculation point, and the step size can be set arbitrarily to calculate the wellbore temperature, wellhead pressure and wellhead dryness distribution at the wellhead. Wellbore pressure and wellbore dryness distribution; based on the wellbore temperature, the wellbore pressure and the wellbore dryness distribution, guide the implementation of corresponding processes on the oilfield site. The invention has good calculation stability and high calculation accuracy, and provides reliable calculation means for the optimal design of injection parameters of the steam+nitrogen mixed system in the wellbore.

The invention discloses a method for measuring a complex degree of coherence of a random optical field by using a mutual intensity-intensity correlation, including the steps of: building a test optical path; rotating a quarter-wave plate to enable the fast axis of the quarter-wave plate to be consistent with a polarization direction of reference light, to obtain light intensity distribution information of a first combined light; rotating the quarter-wave plate to enable the slow axis of the quarter-wave plate to be consistent with the polarization direction of the reference light, to obtain light intensity distribution information of a second combined light; blocking the reference light to obtain light intensity distribution information of to-be-tested light; blocking the to-be-tested light to obtain light intensity distribution information of the reference light; and calculating the amplitude and phase of a complex degree of coherence of the to-be-tested light.