310 results about "Wave vector" patented technology

A method for guiding electromagnetic radiation by providing a photonic crystal made of a bulk material with a predetermined refractive index and having a periodic array of holes with predetermined radius, and feeding to that region an electromagnetic radiation having a wavelength in the fundamental photonic band and so related to the refractive index of the bulk material, to the radius of the holes and to the period of the array that, starting from an isotropic distribution of the wave vectors within a first angular range that is twice the angular extension of the first irreducible Brillouin zone of the photonic crystal, the corresponding group velocity vectors are rearranged as concerns direction and module so that at least 50% of them become directed within a second angular range that is about one-third of the first angular range and the width at half-maximum of the distribution of the modules of the vectors is lower than about two-thirds of the second angular range.

The invention relates to a surface artificial electromagnetic material applied to directional radiation modulation. The material is manufactured by the following steps of: (1) selecting a base metal material; (2) determining the shape of a center feed source and the frequency band of a radiation source; (3) determining the period p, the width w and the groove depth l of a type-a groove to be manufactured; (4) determining the period d, the width a and the depth h of a type-b groove; and (5) manufacturing a period type-A groove and a period type-B groove on one side on a metal substrate so as to obtain the surface artificial electromagnetic material with directional radiation. The surface artificial electromagnetic material can realize the modulation of equivalent wave vectors of metal surface waves. Under the combined action of the type-A groove and the type-B groove, the surface artificial electromagnetic material can achieve the regulation and control on far-field radiation characteristics.

Wave vector division multiplexing (“WVDM”) is a method of free-space multiplexing for optical communications. In WVDM, wave vectors of individual laser beams are manipulated so that each individual laser beam has a unique wave vector. These individual laser beams are multiplexed into an aggregate beam, which is transmitted to a receiver. The receiver separates the individual laser beams on the basis of their unique wave vectors. One area where WVDM is useful is in quantum cryptography. WVDM can also be combined with traditional wavelength division multiplexing (“WDM”) to increase throughput even further.

The present invention relates to a method and system for processing multi-dimensional signal data to determine frequency dependent features therefrom. The multi-dimensional signal data are transformed into space-frequency or time-space-frequency domain, providing second signal data. At predetermined locations of at least a portion of the one of space and time-space of the second signal data a dominant feature corresponding to a largest value of the second signal data is determined. This is followed by the determination of a wave-vector corresponding to the dominant feature at each of the predetermined locations. Finally, a dip map, a frequency map, and an amplitude map are generated using the wave-vectors. The method and system for processing multi-dimensional signal data to determine frequency dependent features therefrom according to the present invention provide a powerful tool for improved and more detailed evaluation of seismic data using dip, frequency, and amplitude maps, resulting in substantially more accurate geophysical surveys.

A technique for calculating traveltime of a seismic wave in three dimensional tilted transversely isotropic (3D TTI) media includes determining a wave vector, defining a unit vector, calculating an angle of the wave vector from an axis and performing a slowness determination. The technique may be practiced as a computer implemented set of instructions, and may be incorporated into measurement equipment.

A method and computer program product for imaging an object are disclosed. The object is illuminated with an electromagnetic wave, characterized by a spectrum of illuminating wavevectors. Electromagnetic waves scattered by the object are detected, and are characterized by a spectrum of detected wavevectors. An aperture equal to or smaller than an instantaneous characterizing wavelength of the illuminating electromagnetic wave is disposed between the source and the detector. At least one of the illuminating and detected wavevectors is varied in magnitude to provide information regarding a scattering characteristic of the object. By applying a forward model of the aperture to derive a three-dimensional scattering model, a three-dimensional reconstruction of the object may be obtained by inverting a detected data function in terms of the forward model.

The invention discloses an optical-fiber sensor, a preparation method and a measuring system. The optical-fiber sensor comprises a D-shaped photonic crystal optical fiber, wherein the cross section of the D-shaped photonic crystal optical fiber is D-shaped, so that the D-shaped photonic crystal optical fiber has a plane on which a nano metal sensing layer is adhered. The optical-fiber sensor disclosed by the invention adopts the D-shaped photonic crystal optical fiber, the D-shaped photonic crystal optical fiber can be a hollow photonic crystal optical fiber, a central hole is filled with a solution for controlling the effective refractive index and dispersivity of transmitting light, and resonance points of surface plasma resonance is changed by controlling the wave vector length of a core mold, so that the movement of resonance wavelength caused by change of external environment is expanded, the sensitivity of the sensor is improved, and high-accuracy refractive index measurement is realized; the optical-fiber sensor, the preparation method and the measuring system can be used for researching the high-sensitivity biochemical reaction analysis.

The invention discloses an ultrathin bi-directional sound obstruction channel. When obstructing sound, the ultrathin bi-directional sound obstruction channel can allow electromagnetic waves, air flow or even objects to pass through. The ultrathin bi-directional sound obstruction channel includes an upper metasurface and a lower metasurface which are arranged in parallel; surfaces of the upper metasurface and the lower metasurface, which are opposite to each other, are symmetrically provided with a plurality of groups of folding structures; each folding structure includes at least five obstruction boards which are arranged side by side; cavities are formed between adjacent obstruction boards; and cross beams are alternately distributed on the obstruction boards in the cavities. According to the ultrathin bi-directional sound obstruction channel of the invention, operation and control on the direction of the wave vector of reflected waves by the upper and lower acoustic metasurface materials are simply utilized, and at the same time, the super thin characteristic and the abnormal reflection function of the metasurfaces are ingeniously utilized, and therefore, acoustic waves of which grazing incidence is along the metasurfaces geometrically, namely, acoustic waves transmitted along the axial direction of the pipeline, are deviated by an angle close to 90 degrees, and after two times of action, the direction of the wave vector of the reflected waves can be opposite to the direction of incident waves, and the acoustic waves can be effectively obstructed at a certain depth of a waveguide.

Systems and methods for producing circular extinction (CE) contrast images of anisotropic samples. Microscope systems for determining circular extinction (CE), the differential transmission of left and right circularly polarized light resulting from circular dichroism (CD) of an anisotropic sample, include mechanically driven optical components and an image detector such as a monochromatic CCD camera to detect light intensities. In one aspect, optical components include a tunable filter, a rotatable linear polarizer and a variable retarder. The tunable filter is adjustable to provide light at a specific desired wavelength. The linear polarizer is adjustable to provide linearly polarized light with a specific wave vector, and the variable retarder is adjustable to produce near perfect circular polarized light at every selected wavelength. For example, in one aspect, the variable retarder includes a linear birefringent plate tiltable around one of its eigenmodes perpendicular to the wave vector of polarized light. The plate may be controllably tilted so that it functions as a perfect λ / 4 plate at each wavelength.

The invention provides a prediction method for current transformer saturation. The prediction method comprises the following steps: detecting a first current output from a high-voltage side current transformer of a transformer, and detecting a second current output from a low-voltage side current transformer of the transformer; calculating a first fundamental wave vector, a first DC (direct-current) component and a first total effective value of the first current, and calculating a second fundamental wave vector, a second DC component and a second total effective value of the second current; generating a current transformer saturation prediction signal according to the first fundamental wave vector, the first DC component, the first total effective value, the second fundamental wave vector, the second DC component and the second total effective value. By the method, the current transformer saturation can be predicted or detected effectively before the differential protection of the transformer caused by the current transformer saturation, so that the maloperation of the differential protection of the transformer can be effectively avoided.