203 results about "Elliptical polarization" patented technology

The present invention provides methods and apparatuses for accurate noninvasive determination of tissue properties. Some embodiments of the present invention comprise an optical sampler having an illumination subsystem, adapted to communicate light having a first polarization to a tissue surface; a collection subsystem, adapted to collect light having a second polarization communicated from the tissue after interaction with the tissue; wherein the first polarization is different from the second polarization. The difference in the polarizations can discourage collection of light specularly reflected from the tissue surface, and can encourage preferential collection of light that has interacted with a desired depth of penetration or path length distribution in the tissue. The different polarizations can, as examples, be linear polarizations with an angle between, or elliptical polarizations of different handedness.

A method and apparatus to remove human features utilizing at least one transmitter transmitting a signal between 200 MHz and 1 THz, the signal having at least one characteristic of elliptical polarization, and at least one receiver receiving the reflection of the signal from the transmitter. A plurality of such receivers and transmitters are arranged together in an array which is in turn mounted to a scanner, allowing the array to be passed adjacent to the surface of the item being imaged while the transmitter is transmitting electromagnetic radiation. The array is passed adjacent to the surface of the item, such as a human being, that is being imaged. The portions of the received signals wherein the polarity of the characteristic has been reversed and those portions of the received signal wherein the polarity of the characteristic has not been reversed are identified. An image of the item from those portions of the received signal wherein the polarity of the characteristic was not reversed is then created.

A switchable transmit and receive phased array antenna (“STRPAA”) is disclosed. The STRPAA includes a housing, a plurality of radiating elements, and a plurality of transmit and receive (“T/R”) modules. The STRPAA may also include either a first multilayer printed wiring board (“MLPWB”) configured to produce a first elliptical polarization or a second MLPWB configured to produce a second elliptical polarization within the housing.

The present invention provides methods and apparatuses for accurate noninvasive determination of tissue properties. Some embodiments of the present invention comprise an optical sampler having an illumination subsystem, adapted to communicate light having a first polarization to a tissue surface; a collection subsystem, adapted to collect light having a second polarization communicated from the tissue after interaction with the tissue; wherein the first polarization is different from the second polarization. The difference in the polarizations can discourage collection of light specularly reflected from the tissue surface, and can encourage preferential collection of light that has interacted with a desired depth of penetration or path length distribution in the tissue. The different polarizations can, as examples, be linear polarizations with an angle between, or elliptical polarizations of different handedness.

A wireless subscriber communication unit (200) comprises an antenna arrangement (202, 330, 430) for radiating and/or receiving electromagnetic signals. A transmitter (220) and/or a receiver (210) is/are operably coupled to the antenna arrangement (202, 330, 430), for transmitting/receiving a radio signal. An antenna arrangement comprises an internal antenna located within the wireless communication unit (200) and an external antenna located substantially outside of the wireless communication unit, such that both the internal antenna (330, 430) and the external antenna (202) co-operate on substantially the same electromagnetic signal. In this manner, by provision of both an internal and an external antenna the wireless subscriber communication unit is able to function adequately should an antenna become disconnected, malfunction, or its performance suffer from impedance mismatching. Preferably, the internal and external antennas can be configured to be orthogonal to one another, thereby providing the wireless subscriber unit with the ability to operate with a substantially circular or elliptical polarization.

An elliptically polarized (EP) dielectric block antenna comprises a linearly polarized (LP) dielectric block antenna and a wave polarizer integrated with the LP dielectric block antenna. The wave polarizer converts the LP wave of the LP dielectric block antenna into an EP wave or a circularly polarized (CP) wave. The wave polarizer is directly integrated with the LP dielectric block antenna by fabricating inclined slots on faces of the dielectric block at an oblique angle to the LP wave direction of polarization. This provides a very compact EP or CP antenna with a broadside or omnidirectional radiation pattern. The EP or CP antenna is excited by an inner conductor of a SubMiniature version A (SMA) connector that can be directly connected to a coaxial line thereby providing a simple feed network for the antenna.

An apparatus and method for measuring the location of one borehole relative to another includes a pair of elongated crossed coils deployed in the first borehole and an instrument containing magnetic field sensors deployed in the second borehole. The crossed coils are energized in quadrature by AC currents producing a rotating, elliptically polarized magnetic field at the second borehole. Mathematical analysis of the magnetic field sensor readings determines the location of the second borehole relative to the first. Both the distance and the rotational direction to the second borehole are determined as a function of depth of the sensors relative to that of the pair of crossed coils. No knowledge or measurement of the rotational orientation of the crossed coil in the first borehole is needed. Any twisting of the long coil in the borehole can be evaluated by noting the relative phase of the received elliptically polarized field as the depth of measurement is varied, and the relative distance between the boreholes and the corrections needed due to such twisting are determined.

A radar level gauge (RLG) is provided for determining a filling level of a filling material contained in a container by transmitting and receiving elliptically or circularly polarized waves. The RLG comprises: a feeding circuitry for feeding and receiving two essentially orthogonal elliptically polarized waveguide modes, one of the modes for transmission and another mode for reception; an antenna for transmitting the waveguide modes towards the filling material and for receiving reflected signals; and a waveguide to provide signals between said feeding circuitry and the antenna. Further, the feeding circuitry comprises: a microwave generating unit (TX); a microwave receiving unit (RX); at least three feeding probes being at least partly exposed to the interior of the waveguide; and a coupling circuitry for transferring and feeding signals between each feeding probe and the microwave generating unit and/or the microwave receiving unit. At least the coupling circuitry and the feeding probes are implemented on a common printed circuit board (PCB), and the printed circuit board is arranged transversely over the waveguide.

There is provided a technique for securing a large examination space in a tunnel type MRI device without inviting increase of manufacturing cost and without significantly reducing irradiation efficiency or uniformity of the irradiation intensity distribution in an imaging region. Between rungs of a partially cylindrical RF coil, which coil corresponds to a cylindrical RF coil of which part is removed, there are disposed half-loops generating magnetic fields, which are synthesized with magnetic fields generated by loops constituted by adjacent rungs of the partially cylindrical RF coil and rings connecting the rungs to generate a circularly polarized or elliptically polarized magnetic field. Further, high-frequency signals of the same reference frequency having a desired amplitude ratio and phase difference are supplied to the partially cylindrical RF coils and half-loops.

A switchable transmit and receive phased array antenna (“STRPAA”) is disclosed. The STRPAA includes a housing, a plurality of radiating elements, and a plurality of transmit and receive (“T/R”) modules. The STRPAA may also include either a first multilayer printed wiring board (“MLPWB”) configured to produce a first elliptical polarization or a second MLPWB configured to produce a second elliptical polarization within the housing.

An RF coil apparatus for generating an elliptical polarization field includes an RF coil assembly having a pair of independent drive channels connected thereto. The drive channels are driven such that an elliptical polarization field is generated in a volume-of-interest within the RF coil assembly. The elliptical polarization field is generated about a subject having a generally elliptical cross-section disposed within the volume-of-interest.

A method and device for measuring displacement delay and axle direction of 1/4 wave-plate. Its principle is: uses light intensity detecting technique of elliptical polarization, setslambda/4 Fresnel double diamond and 1/4 wave-plate between polarizer and analyzer in turn, rotates wave-plate and analyzer to different position and detecting output light intensity, finally achieves displacement delay and axle direction of 1/4 wave-plate. The invention can detect displacement delay and axle direction of 1/4 wave-plates with different wavelength in a wide spectral range, which has high detecting precision, convenient operation and automatic measurement.

The invention discloses a short-distance optical amplification module group, an amplification method, and an amplification system. The module group comprises a first phase delay sheet, an imaging lens, a second phase delay sheet, and a reflection-type polarizing film. The first phase delay sheet is disposed on a transmission path of an optical image having a first linear polarization direction, and the imaging lens is disposed on a transmission path of an optical image having an elliptical polarization direction or a circular polarization direction. The second phase delay sheet is disposed on one side of the second optical surface of the imaging lens, and the second linear polarization direction is orthogonal to the first linear polarization direction. By adopting the first phase delay sheet, the imaging lens, the second phase delay sheet, and the reflection-type polarizing film, the optical image can be amplified by the imaging lens after being reflected by the reflection-type polarizing film, and therefore the requirement of the optical amplification multiple of the optical image can be satisfied, and in addition, by arranging the second phase delay sheet and the reflection-type polarizing film in an attached manner, the size and the volume of the optical module group can be further reduced.

Systems, illumination subsystems, and methods for increasing fluorescence emitted by a fluorophore are provided. One system configured to measure fluorescence of particles includes an illumination subsystem configured to illuminate the particles with light having linear polarization oriented in a non-vertical direction, circular polarization, or elliptical polarization. The polarization of the light causes fluorescence emitted by the fluorophore to be brighter than fluorescence emitted by the fluorophore when illuminated with linearly polarized light oriented in a predominantly vertical direction or non-polarized light. The system also includes a detection subsystem configured to generate output signals responsive to the fluorescence emitted by the fluorophore.

The invention discloses a metasurface polarization regulator. The metasurface polarization regulator is composed of five structural layers. The top layer and the bottom layer are period metal micro-structure layers, the middle layer is a metal film layer, and the top layer, the bottom layer and the middle metal layer are separated by the insulating medium layers. The regulator works in a near infrared band, and the whole thickness of a system is far smaller than the working wavelength; the transmission rate of normal incidence electromagnetic waves is higher than 80%; as geometric parameters of the structure and the physical performances of relative materials are adjusted, the whole phase interval of 0-360 degrees can be covered with the phase difference between transmitted waves of an x component and transmitted waves of a y component, and therefore free adjustment of the polarization state of the electromagnetic waves can be achieved; for example, the transmission polarization state of electromagnetic waves transmitted through linear polarization can be transformed into the circular polarization state, the elliptical polarization state or the linear polarization state or even the complete polarization inversion state.

A magnetic resonance system obtaining magnetic resonance exposures of an examination subject, has an examination tunnel, a whole-body antenna with two connection terminals. The whole-body antenna cylindrically extends around the examination tunnel along a longitudinal axis. The system has a radio-frequency supply device in order to respectively supply the whole-body antenna with radio-frequency signals for emission of a radio-frequency field in the examination tunnel. The radio-frequency supply device has a radio-frequency generator for generation of a radio-frequency signal, a signal splitter that divides a radio-frequency signal coming from the radio-frequency generator into two partial signals that are phase-shifted by 90° relative to one another. Two radio-frequency feed lines are connected with the two connection terminals of the whole-body antenna. Via these radio-frequency feed lines, the two partial signals are fed into the whole-body antenna. The whole-body antenna has an intrinsic transmission characteristic such that a radio-frequency field is emitted that is elliptically polarized in a defined manner in a plane lying perpendicular to the longitudinal axis (at least in the unloaded state of the examination tunnel).

A method for optical stress analysis comprises the steps of directing an incident beam of polarized light to the sample to be analyzed and analyzing a light bundle exiting the sample in two detection channels extending perpendicular to one another with respect to the polarization direction, providing that the incident beam is elliptically polarized, carrying out the elliptical polarization with an elliptic shape having a comparatively large ratio of the large principal axis to the small principal axis, the direction of rotation of the elliptical polarization of the incident beam changing periodically and using two alternative states of the direction of rotation for each measurement process, adjusting the detection channels which extend perpendicular to one another corresponding to the position of the principal axes of the ellipse and carrying out the difference between two measurements consecutively with the same beam intensity of the incident beam and the same ratio of principal axes, but with opposite direction of rotations of the elliptical polarization, being given by the two detection channels. An arrangement in accordance with the method is also disclosed.

The invention belongs to the technical field of optical thin film optical constant measurement, and particularly relates to a method for measuring optical constants of a Gel-xCx thin film infrared spectroscopy area. The method for measuring the optical constants of the Gel-xCx thin film infrared spectroscopy area comprises the following steps: measuring a thin film infrared transmitted spectrum so as to confirm the position of an absorption peak, establishing a thin film optical constant physical model according to the position of the absorption peak, and calculating by using an infrared transmitted spectrum and elliptical polarization spectrum combined composite target retrieval method to obtain optical constants such as the refractive index, the extinction coefficient and the physical thickness of a Gel-xCx thin film. Specifically, according to the scheme, the accurate position and the absorption magnitude of the absorption peak are confirmed according to the transmitted spectrum of a single-layer infrared thin film, on the basis, and regression calculation on an ellipsometry spectrum is performed, so that the optical constants of the thin film are obtained. The method has the advantages that the long optical constants of the thin film, particularly the optical constants of infrared thin films with absorption peaks, can be accurately obtained.

The invention belongs to the technical field of an optical electronic device and particularly relates to an elliptical polarization instrument sample room device with variable temperature and a temperature change method thereof. The device provided by the invention comprises a gas bottle, an air valve, an electromagnetic valve, a Dewar bottle, a sample room, a sample table, a heating resistor, a temperature sensor, a temperature controller and the like, wherein the sample room is divided into an upper cavity and a lower cavity; the lower cavity is in a cuboid shape; the side of the upper cavity is in a trapezoid shape; and optical windows are formed on the inclined planes at the two sides of the upper cavity. The temperature change method provided by the invention is divided into a high temperature mode and a low temperature mode, wherein in the low temperature mode, low-temperature liquid is heated by utilizing normal-temperature gas to generate low-temperature refrigerating gas and the low-temperature refrigerating gas is injected into the sample room through a heat-insulating gas pipeline, thus the sample table reaches the set low temperature; and in the high temperature mode, the heating is carried out through the heating resistor, thus the sample table reaches the set high temperature. The device provided by the invention has the advantages of convenient manufacture and low cost, and the temperature change method provided by the invention has the advantages of good effects and strong practicability and can be used for various elliptical polarization spectral measurements.

The invention relates to the field of seismic exploration, in particular to a surface wave pressing method which comprises the steps of: carrying out Hilbert conversion on single-component seismic signals; forming a plurality of signals by using the signals after Hilbert conversion; computing corresponding elliptical polarizability according to the signals; and pressing according to the obtained elliptical polarizability to obtain pressed signals. By adopting the surface wave pressing method of the invention in a theoretical simulation test, Rayleigh surface waves after instant polarization filtering can be well attenuated, and reflected waves are obvious; generally indicated by the application effect of outdoor actual data, by adopting the surface wave pressing method of the invention, the energy of surface waves can be well pressed and the pressed surface waves can better keep the true amplitude of a seismic record.