313 results about "Wave vector" patented technology

Disclosed is an optical element that includes: a light guide body into which light from a light-emitting element enters; carrier generation layer (6) formed in the light guide body, in which carriers are generated by the light from the light guide body; plasmon excitation layer (8) stacked on carrier generation layer (6), which has a plasma frequency higher than the frequency of light generated when carrier generation layer (6) is excited by the light from the light-emitting element; and wave vector conversion layer (10) stacked on plasmon excitation layer (8), which converts light incident from plasmon excitation layer (8) into light having a predetermined exit angle to output the light. Plasmon excitation layer (8) is sandwiched between low dielectric constant layer (7) and high dielectric constant layer (9).

The invention belongs to the field of photoelectric technology, and specifically relates to a photoelectric material adjustable absorption enhancing layer based on graphene surface plasmon. Graphene forming the enhancing layer is a thin film formed by single-layer graphene and having micro-nano scale structural features, graphene is doped to a certain concentration, and the Fermi level Ef of the graphene is larger than 0.1eV or smaller than -0.1eV, so that the graphene becomes a surface plasmon material; and the micro-nano structure is used for realizing wave-vector matching between incident light and a graphene surface plasmon mode, and under irradiation of the incident light, the doped graphene micro-nano structure generates surface plasmon, thereby realizing a local area of focusing. The absorption enhancing layer is applied to the upper side of photoelectric material used by photoelectric devices such as a solar cell and a photoelectric detector, can improve the absorption efficiency of the photoelectric material, and can realize active regulation and control of absorption characteristics of the photoelectric material, thereby expanding application of the photoelectric material in fields of spectrum-adjustable selective detection and the like.

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.

This invention concerns the relaying protection field of the power transmission line, especially concerned with the occasion of electric current differential protection and phase differential protection proceeding in the extra-high voltage and ultra-high voltage long distance ling. In order to solve the problem of which the traditional electric current differential protection and phase differential protection is influenced largely by distributed capacitance's current, thereby to improve the sensitivity of relaying protection, safety and reliability of the operation, the technique plan adopted by this invention is: according to a transmission line model formula, calculate a side of the line current moment flow, get calculated value, then using a filtering algorithm, filter the current actual value and calculate value, get the fundamental wave vector separately.

The invention discloses a method for preparing a surface plasmon polariton coupled nano array. The method comprises the following steps: performing deep reactive ion etching on a substrate by adopting a nano-scale etching mask which is manufactured by electron beam exposure, and then performing metallic membrane plating to obtain a three-dimensional 'metal nano structure array-nano space layer-metallic film' structure. The metallic nano structure generates local electromagnetic field resonance of photon and free electron to generate a very strong local surface plasmon polariton, and a diffraction effect provides wave vector compensation to excite a propagating type surface plasmon polariton of the metallic film so as to form local surface plasmon polariton-propagating type surface plasmon polariton coupling, so that light is restrained in a nano scale to initiate very strong surface local near field enhancement between a metal and a medium interface. The structure manufactured by the process disclosed by the invention can promote new mechanism exploration of the surface plasmon polariton, and has important application prospects in the fields of metamaterials, ultrahigh-sensitivity optical biosensing and the like.

The invention discloses a multi-wave wave field separation and synthesis method and a system. The method comprises the following steps: carrying out vector superposition on all wave vectors within a quadrant in which longitudinal wave / transverse waves are positioned in a certain time window; obtaining longitudinal wave / transverse wave unit wave vectors based on the superposed vector; at a moment in the time window, separating longitudinal wave / transverse wave vector along the R axis / Z axis respectively, forming an affine coordinate system in direction of the longitudinal wave / transverse wave vector, and converting the separated longitudinal wave / transverse wave vector to the affine coordinate system based on an included angle between the longitudinal wave / transverse wave vector and the R axis and an included angle between the longitudinal wave / transverse wave vector and the Z axis; and based on the unit wave vector, separating the longitudinal wave / transverse wave vector at a moment in the time window to obtain the parallel parts of the longitudinal wave / transverse wave vector and relevant unit wave vector under the affine coordinate system for output. The invention can separate the wave fields of the longitudinal wave vector and the transverse wave vector, recover the vector amplitude of the longitudinal wave / transverse wave, suppress noise, and improve accuracy of earthquake data analysis, thereby meeting need of earthquake data analysis and explanation.

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 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.

Light source layer (4) includes substrate (10) and a pair of layers, namely, hole-transport layer (11) and electron-transport layer (13), formed on substrate (10). Directional control layer (5) includes plasmon excitation layer (15) stacked on a side of light source layer (4), which is opposite to the side of substrate (10) of light source layer (4), and which has a plasma frequency higher than a frequency of light output from light source layer (4), and wave vector conversion layer (17) stacked on plasmon excitation layer (15), which converts light incident from plasmon excitation layer (15) into light having a predetermined exit angle to output the light. Plasmon excitation layer (15) is sandwiched between low dielectric constant layer (14) and high dielectric constant layer (16).

The invention relates to methods, devices, systems and uses of such systems for the generation and detection of electromagnetic fields carrying orbital angular momentum. An electromagnetic wave placed in a resonator having a closed-loop waveguide supporting a guided wave propagating at resonance with angular order, p, and with an angular grating patterned in the closed-loop waveguide, the angular grating having a integer number, q, of grating elements. The angular grating selectively couples the guided wave mode to a free space radiation mode having an OAM quantity, l, and out-of-plane wave vector component, krad,z, and wherein significant coupling to the grating occurs only when the following wave matching condition is satisfied: l=p−mq where: m is the diffraction order of the angular grating, m=1, 2, 3, . . . ,.

The invention discloses a holographic waveguide display device of a high diffraction efficiency and a grating coupling method of the holographic waveguide display device. The holographic waveguide display device comprises a micro display (201), a collimating lens (202), a diaphragm (203), a waveguide (204), a coupling-in grating group (C201) and a coupling-out grating group (C202); the micro display (201) is positioned under the lower surface of the waveguide (204); and the coupling-in grating group (C201) and the coupling-out grating group (C202) are tightly connected with the right and leftends of the upper surface of the waveguide (204) respectively. According to the holographic waveguide display device, a 1D sub-wavelength binary grating is coupled to a reflective body holographic grating, the diffraction energy level can be re-distributed under the condition that wave vector matching and position matching are ensured, the diffraction efficiency in the main diffraction direction reaches the maximum, energy of a light beam diffracted into the eyes is maximal, and high-efficiency holographic waveguide display is realized.

A technique is disclosed for identifying network traffic. The traffic data is converted into a wave vector. The wave vector is compared with a wave template. It is then determined whether the wave vector is substantially similar to the wave template.

Disclosed is an optical element that includes: carrier generation layer (16) in which carriers are generated by light from light guide body (12) into which light from a light-emitting element enters; plasmon excitation layer (17) that has a plasma frequency higher than the frequency of light generated when carrier generation layer (16) is excited by light from the light-emitting element; and wave vector conversion layer (18) that converts surface plasmon generated by plasmon excitation layer (17) light having a predetermined exit angle to output the light. Plasmon excitation layer (17) is sandwiched between two layers having dielectric properties. The effective dielectric constant of the incident side portion of plasmon excitation layer (17) including an entire structure stacked above light guide body (12) side is higher than that of the exit side portion of plasmon excitation layer (17) including the entire structure stacked above wave vector conversion layer (18) side and the medium in contact with wave vector conversion layer (18).

The invention discloses a method for separating a three-dimensional three-component vector wave field. The method comprises the following steps of: establishing an orthorhombic O-Z-R-T three-dimensional coordinate system; detecting wave vector directions of a vertical wave, a fast transverse wave and a slow transverse wave; establishing a first affine coordinate system according to the wave vector direction of a projection vector of the vertical wave on an incidence face, and the wave vector direction of the fast transverse wave; rotatably converting vectors Z and R of a receiving coordinate system in the first affine coordinate system, so as to obtain a projection vector of the vertical wave on an R-O-Z plane, and the quick transverse wave; and rotatably converting the projection vector of the vertical wave on the R-O-Z plane and a polarization projection vector on a T axis in a second affine coordinate system, so as to obtain the vertical wave and the slow transverse wave. The method and the device provided by the invention can separate the vector wave fields of the vertical wave P, the fast transverse wave SV and the slow transverse wave SH.

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.

The invention relates to a periodic nanostructure-based biosensor and a preparation method thereof. The biosensor is a surface plasmon resonance biosensor, and comprises a substrate, a noble metal thin film and a periodic nanostructure, wherein the noble metal thin film is arranged on the substrate; the periodic nanostructure is arranged on the noble metal thin film; the periodic nanostructure comprises a plurality of through-hole structures which are equally distributed and are parallel to each other; and the periodic nanostructure is used for providing wave vector matching needed by exciting surface plasma. The periodic nanostructure-based biosensor can overcome disadvantages of huge size in a conventional biosensor and provide the wave vector matching needed by exciting the surface plasma. Besides, all production processes are compatible with those of a standard semiconductor technology. The periodic nanostructure-based biosensor is simple in production processes, has relatively small size and is easy to integrate.

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 automatic testing method and system for a transmission characteristic of a microwave / millimeter wave vector modulator. The system comprises a small signal transmission characteristic testing system and a large signal transmission characteristic testing system; and the large signal transmission characteristic testing system includes a large signal power compression characteristic testing system and a large signal phase compression characteristic testing system. The automatic testing system is allocated flexibly, is suitable for automatically testing the transmission characteristic of various millimeter wave frequency sections, and can universally realize the automatic testing of the transmission characteristic of the microwave / millimeter wave vector modulator under the large signal condition and under the small signal condition; moreover, the invention also overcomes the trouble of lacking pf the large signal phase compression characteristic and the large signal power compression characteristic testing method and the automatic testing system in the domestic microwave / millimeter wave vector modulator at present, and avoids the defects, such as low efficiency, low precision, a plurality of uncertain factors and the like in the manual testing.

A fiber-type optical coupler has two optical fibers including a core on which a slanting Bragg diffraction grating is formed and a first cladding and a second cladding bordered with a boundary plane close to the core. The two optical fibers are placed by approximating the boundary plane almost contacting the core, making respective optical axes almost parallel and also making slanting directions of the respective Bragg diffraction gratings almost parallel. A wave vector of the slanting Bragg diffraction grating is located in a plane made by a normal set up on the boundary plane almost contacting the core and the optical axis of the core, and an angle θ made by the wave vector and the optical axis is 0 degree<θ<90 degrees. In addition, a refractive index of the second cladding is lower than that of the first cladding.

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.

The invention discloses a voltage balance and power balance control method of a cascaded H bridge converter. The method comprises the following steps: (1) double closed loop control used for providing a same modulated wave vector to each H bridge; (2) voltage balance control; and (3) power balance control, wherein the voltage balance control and the power balance control improve a modulated wave vector respectively, and a reconstructed modulated wave vector is obtained and is taken as a modulation signal of each H bridge. According to the invention, adding an extra circuit is not needed, compared with a method of directly modifying a modulation ratio, direct current side voltage of each H bridge maintains balanced, voltage ripple is basically consistent, each H bridge flows through active power distributed according to needs, reactive power is distributed according to equivalent, and the method has a wider constraint scope and is suitable for an occasion of large load unbalance.

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.

The invention relates to a method and a system for generating a double-exponential Bessel Gaussian beam, which is designed for realizing superposition of multiple Bessel Gaussian beams with differenttransverse wave vectors and specific amplitude. A linearly-polarized Gaussian beam firstly passes through a vortex phase plate, a phase factor is introduced to the linearly-polarized Gaussian beam, and a Gaussian vortex beam is generated; the Gaussian vortex beam then passes through an amplitude spatial light modulator which is loaded with at least two circular amplitude holograms, through regulating the transmittance of the circular amplitude hologram, the amplitude of the Gaussian vortex beam (the double-exponential Bessel Gaussian beam) is further regulated, and a double-exponential BesselGaussian beam angular spectrum function is generated; and finally, Fourier transform is carried out to generate the double-exponential Bessel Gaussian beam. The double-exponential Bessel Gaussian beamsuperposition flexibility is higher, and the operation of generating the double-exponential Bessel Gaussian beam is simple.

A semiconductor laser includes a laser resonator (1) having a planar active region (3), a first (2) and a second (6) wave-guide layer that define the active region (3). The resonator (1) has a shape that is defined by a perimeter, along which the first layer (2) radiation guide has a plurality of cuts (4) forming a lattice. The cuts are made as at least two adjacent slits (4a, 4b) and a zone between the slits in which an uncut portion (5a) of wave-guiding layer is present. In the case of a circular semiconductor laser, the number of cuts (4) is a prime number, or an odd number that is a multiple of a prime number, the prime number being greater than or equal to five. This way, it is avoided that resonance modes evolve outside of the zone with the cuts, or in any case with a component that is different from zero of the wave vector in a radial direction, and a pure whispering gallery operating mode is obtained, with maximum of the emitted radiation that evolves in a vertical direction, i.e. orthogonal to the plane of the laser resonator, and without the laser emitting radiation evolving in a radial direction.

The invention relates to a signal photon detector based on polarization unrelated frequency up-conversion; the signal photon detector comprises a lithium niobate crystal which is formed by periodically superposing four parts and is periodically polarized, wherein for a first part and a fourth part, the periodic structures are same, the period length is lA and meets the quasi-phase matching condition of frequency up-conversion, and the period number is NA so that all signal lights can be converted into sum frequency lights; a second part is in a periodic structure used by reciprocal lattice vectors for compensating mismatching of wave vectors coupled and polarized by signal lights, and the period length is lB and meets the phase matching condition of signal light polarization rotation; and a third part is in a periodic structure used by reciprocal lattice vectors for compensating mismatching of wave vectors coupled and polarized by sum frequency lights, the period length is lC and meets the phase matching condition of signal light polarization rotation. An external direct-current power supply is applied to y-surfaces of the second part and the third part of a sample so as to realize the periodic modulation of optical coefficients, thereby leading the polarization direction of corresponding light waves to rotate. The signal photon detector is practicable in preparation and has wide application prospect in fields of quantum communication and photo-communication.