281 results about "Degree of polarization" patented technology

In embodiments of the present invention, systems and methods of a non-invasive imaging device may comprise an illumination source comprising an incident light source to direct light upon skin, and a detector for detecting the degree of polarization of light reflected from the skin. A system and method of determining a skin state may be based on an aspect of the polarization of the reflected light.

There are provided a thin wire grid polarizer having a high transmittance, a high quenching ratio and a high degree of polarization, and a method for producing the same at low costs. A fluoridated polyimide thin film 12, a hydrophilic thin film 13 and a hydrophobic thin film 14 are sequentially stacked on a glass substrate 11 to be pressed by a die 1 from the side of the hydrophobic thin film 14 to transfer the fine pattern of groove forming protrusions 3 of the die 1 to the hydrophobic thin film 14 and hydrophilic thin film 13 by the nano-imprinted lithography technique, and then, metal fine wires are caused to grow by plating.

A Vertical Cavity Surface Emitting Laser (VCSEL) and its fabrication are taught which incorporate a high contrast grating (HCG) to replace the top mirror of the device and which can operate at long-wavelengths, such as beyond 0.85 μm. The HCG beneficially provides a high degree of polarization differentiation and provides optical containment in response to lensing by the HCG. The device incorporates a quantum well active layer, a tunnel junction, and control of aperture width using ion implantation. A tunable VCSEL is taught which controls output wavelength in response to controlling a micro-mechanical actuator coupled to a HCG top mirror which can be moved to, or from, the body of the VCSEL. A fabrication process for the VCSEL includes patterning the HCG using a wet etching process, and highly anisotropic wet etching while precisely controlling temperature and PH.

A wire grid polarizer has a resin substrate 1 having grid-shaped convex portions 1a, a dielectric layer 2 provided to cover the grid-shaped convex portions 1a of the resin substrate 1 and at least part of side faces 1b of the portions, and metal wires 3 provided on the dielectric layer. The wire grid polarizer has a microstructural concavo-convex grid structure having grid-shaped convex portions, is not limited in structure, and has both the excellent degree of polarization and excellent transmittance over a wide range in the visible region.

A method, apparatus, and computer program product for identifying features in a sample by analyzing Mueller matrices to calculate an average degree of polarization, a weighted average degree of polarization, a degree of polarization map, a degree of polarization surface. Also, a method, apparatus, and computer program product for identifying features in a sample by analyzing Mueller matrices to calculate depolarization relative to a retardance axis and/or a diattentuation axis, and to calculate a ratio of diattenuation to polarizance or ratios of row and column magnitudes. Also, a method for retinal polarimetry, including a non-depolarizing light tube configured for insertion into the eye.

In a method of polarization optical time-domain reflectometer (P-OTDR) for measuring a parameter of an optical transmission path, for example an optical fiber, by transmitting pulses of light into the path and measuring the state of polarization of backscattered light against distance, statistical analysis of the degree of polarization (DOP) of the backscattered signal is used to detect sections of an optical transmission path for which mode-coupling behaviour (long h) leads to high PMD. Preferably, successive DOP measurement are taken with different state of polarization, SOP, for the P-OTDR light source.

A multi-energy polarization imaging method consisting of a multi-fusion, dual-rotating retarder/multiple-energy complete Mueller matrix-based polarimeter and dual-energy capabilities, has been invented. The term multifusion describes the use of several imaging functions altogether such as polarimetric imaging, dual-energy subtraction, multifocal imaging and other. By substracting polarimetric parameters such as degree of polarization, degree of linear polarization, degree of circular polarization, respectively, obtained with interrogation light beams of wavelengths λ₁ and λ₂, he system, enhanced imaging is obtained. The system includes a light source for illuminating a target with a first quantity of light having a first wavelength and a second quantity of light having a second wavelength, the first and second wavelengths being different. A polarization-state generator generates a polarization state for each of the first and second quantities of light, and includes a first polarizer through which the first and second quantities of light are transmitted before entering a first waveplate. A polarization-state receiver evaluates a resulting polarization state of the first and second quantities of light following illumination of the target, the polarization-state receiver including a second waveplate through which the first and second quantittes of light are transmitted before entering a second polarizer. An optical image-capture device captures a first image of the target illuminated by the first quantity of light and a second image of the target illuminated by the second quantity of light. A processing unit assigns a weighting factor to at least one of the first and second images and evaluates a weighted difference between the first and second images to generate a multi-energy image of the target.

Optical signal-to-noise ratio (OSNR) monitoring methods and apparatus are described. A tunable optical filter filters an optical channel containing an optical signal and noise. The total signal and noise power at the output of the filter is measured as the transmittance passband of the filter is varied and the maximum and minimum powers are determined. The ratio between the maximum and minimum powers is then used to determine the OSNR of the optical channel, which, for example, can be a wavelength channel in a wavelength division multiplexing (WDM) system. The ratio of the maximum signal power to the minimum signal power and the ratio of the maximum noise power to the minimum noise power are pre-determined based on the signal modulation format type and filter passband characteristics. Because the OSNR monitoring method and apparatus rely on information obtained after spectrally filtering the signal and noise, their operation is independent of any transmission effect that does not affect the optical power spectra of the signal and the noise or affects them in a known manner. For example, effects such as chromatic dispersion (CD), polarization-mode dispersion (PMD), and changes in the signal degree of polarization (DOP) and noise DOP will not affect the OSNR reading thus obtained.

An exposure apparatus for exposing a pattern of a reticle onto a plate using a light from a light source and an optical system includes a measuring part for obtaining polarization information of the light that has passed the optical system, the polarization information including at least one of polarized light intensities, a ratio between the polarized light intensities, a degree of polarization, and a retardation of two orthogonal directions that are both parallel to the optical axis, and a controller for controlling, based on a measurement result by the measuring part, at least one exposure parameter of the light source and the optical system.

In image capturing processor in one embodiment comprises: an image capturing section including an image sensor that captures a polarization image of an object being illuminated with an illuminating light beam; and an image processing section. The image processing section has: a light intensity image generator which generates a light intensity image based on the output of the image sensor; a polarization degree image generator which generates a polarization degree image by calculating the degree of polarization on a pixel-by-pixel basis; a retouching section which generates a retouched polarization image by enhancing the degree of polarization of the polarization degree image at depressions on a micro-geometric surface of the object and by correcting at least one of its hue, saturation and value; and an image synthesizing section which synthesizes the retouched polarization image and the light intensity image together.

Source light of unknown polarization is input into a polarization controller. The polarization controller transforms the polarization of the source light to a plurality of different polarizations. The transformed source light output by the polarization controller is input to a fixed polarizer, which passes a maximal transmitted intensity of the transformed source light at a given transformation perpendicular to an axis of propagation of the source light. The polarizer passes a minimal transmitted intensity of the transformed source light at a transformation orthogonal to the transformation at which the maximal transmitted intensity is passed. The discriminated transformed source light output by the fixed polarizer is input to a light-wave power meter, which measures the intensity thereof. The maximal and minimal measured transmitted intensities of the discriminated transformed source light can be used to determine the DOP of the source light. In the alternative, Mueller calculus can be used to determine the degree of polarization when at least four polarization transformations are performed by the polarization controller and angles by which a half-wave plate and a quarter-wave plate of the polarization controller are rotated are known.

The invention discloses a high-linearity degree-of-polarization quantum-well infrared detector with a plasmon micro-cavity coupled structure. The detector is composed of an upper metal grating layer, a quantum-well infrared photovoltaic conversion activating layer and a lower metal reflecting layer, wherein the upper metal grating layer is formed by metal strips. The detector has the advantages that under the mode selection effect of an electromagnetic wave near-field coupled micro cavity formed by plasmon resonance between the upper metal grating layer and the lower metal reflecting layer, photons capable of entering the micro cavity are mainly photons capable of achieving resonance with a detected wavelength polarization mode; the direction of electric vectors of the photons entering the micro cavity is changed to the z direction from the x direction by being modulated in a micro-cavity mode, and the photons can be absorbed by quantum-well sub-bands in a transition mode to achieve the photovoltaic conversion process. With the advantages, the polarization coupled structure can greatly improve the extinction ratio of polarization responses, and extremely-high polarization distinguishing capacity of the detector is achieved.

The invention relates to a polarization navigation real-time positioning method based on all skylight degree of polarization information. Aiming at the polarization navigation positioning problem, atfirst, the degree of polarization information of observation points of all skylight is acquired by a compound eye simulated polarization sensor, three optimal observation points in the degree of polarization information measured by the compound eye simulated polarization sensor are selected, the degrees of polarization of the three observation points are used as resolving input information, and are combined with the space geometry relation among the selected three observation points to obtain unit sun vector information in a vector system; then the three-dimensional attitude information of a vector at the current moment is acquired by an attitude sensor, and an attitude conversion matrix is acquired; next, the unit sun vector in the vector system is converted into a unit sun vector in a geography system by the attitude conversion matrix; and at last, through inquiring position information of a module calculation vector through an astronomical ephemeris, the polarization navigation positioning function is realized. The method is high in real-time performance, relatively high in precision, and relatively high environmental suitability, and can complete the positioning in a three-dimensional space.

Devices and techniques that use a polarization controller and a feedback control to the polarization controller to systematically control the polarization of light output from the polarization controller in measuring the polarization dependent loss (PDL) of an optical device or material that receives the light from the polarization controller or the degree of polarization (DOP) of a light beam directed into the polarization controller.

To generate light with the degree of polarization zeroed and the spread of an optical spectrum suppressed even with temporal overlapping between optical pulses each of which is polarized orthogonally to the succeeding pulse, a polarization scrambler includes an optical pulse generator that generates optical pulses with an intensity waveform repetition period T/2 and an electrical field repetition period T in which the same intensity waveform is repeated every repetition period T/2 and in which phase is inverted every repetition period T/2, and an orthogonal polarization delay unit which receives each of the optical pulses, separates the optical pulse into two optical pulses with orthogonal states of polarization, and relatively shifts the temporal position of one of the two optical pulses from that of the other optical pulse by (2n−1)T/4 (n is a natural number) to generate light in which each pulse is polarized orthogonally to a succeeding pulse.

A polarizing film, satisfying DI′/P′≦4.3×10⁻⁴ which expresses relation between degree of polarization P′, and depolarization index DI′ calculated by the equation below is disclosed. X represents a value calculated by the equation below, provided that a polarizing plate having degree of polarization of P, the polarizing film, and a polarizing plate having degree of polarization P, having azimuths of transmission axes of a°, b° and c°, respectively, are stacked in this order as viewed from a light source, to give brightness written as [a/b/c].

A polarizing plate comprising a uniaxial stretched polyvinyl alcohol resin film with iodine adsorbed thereto in an oriented state and a protection film bonded to at least one surface of the resin film. The polarizing plate has a single transmittance of about 42.5% or more, a degree of polarization of about 99% or more, and a neutral coefficient Np of 0 to about 4 which is calculated from expression (I), and the polarizing plate also satisfies the relationship represented by expression (II); <paragraph lvl="0"><in-line-formula>Np=|{square root}{square root over ((Pa*)2+(Pb*)2)}-{square root}{square root over ((Qa*)2+(Qb*)2)}| (I) </in-line-formula>wherein Pa*, Pb*, Qb*, and Qa* respectively denote a* and b* in a parallel hue and a* and b* in a perpendicular hue in L*a*b* color system; <paragraph lvl="0"><in-line-formula>{square root}{square root over ((Pa*)2+(Pb*)2)}<4.5 (II). </in-line-formula>The resultant polarizing plate enables neutral white in the case of white display and neutral black in the case of black display, bright white display, and high-contrast display.

The invention provides a device and detecting method for restraining polarization crosstalk measuring noise by the adoption of a light source. The device is composed of a broadband light source, a polarization device to be detected, an optical path correlator, a difference detecting device, an optical signal converting device and a signal recording device. The device is characterized in that the broadband light source is a low coherent light source with high degree of polarization, and a polarization device provided with high extinction ratio is arranged behind the light source. The detecting method comprises the steps that a polarization state controller is connected between the light source and the polarization device, and the polarizing angle of line polarization light and the polarization device are overlapped with each other seriously through adjusting the polarization state of the output light of the light source. According to the device, the high degree of polarization light source and the high extinction ratio polarization device are combined, the measuring noise in the optical coherent domain polarization can be restrained through increasing the extinction ratio of signal light injected into the device to be detected, and measuring accuracy to the device polarization feature of the device is improved. The device and detecting method for restraining polarization crosstalk measuring noise by the adoption of the light source are simple in structure, excellent in performance and easy to adjust, and can be widely applied to the field of high accuracy measuring and analyzing to optical performances of optical type polarization-maintaining devices and the like.

The invention relates to the field of display technologies, and discloses a backlight module and a liquid crystal display device. The backlight module comprises a light guide plate, an optical membrane material located on the light-emitting side of the light guide plate, and an optical orientation membrane located on the light-emitting side of the optical membrane material. The optical orientation membrane comprises an orientation layer, the orientation layer is provided with a plurality of first light blocking walls arranged in parallel, light-transmitting areas are arranged between any two adjacent first light blocking walls, and the side, facing towards the corresponding light-transmitting area, of each first light blocking wall is the light blocking face. The incidence angle of light emitted from the backlight module through the optical orientation membrane on the light-entering face of a lower polaroid is small, then, the degree of polarization of refracted ray emitted from the light-emitting face of the liquid crystal display device is reduced, and the possibility of seeing image information when observers watch the liquid crystal display device in a naked-eye mode on two sides of the liquid crystal display device in the arrangement direction of the first light blocking walls is reduced. Thus, according to the liquid crystal display device provided with the backlight module, peep prevention display can be well achieved.

A pollen sensor and method for detecting pollen which discriminates pollen particles floating in air from other particles on a real time basis. The pollen sensor includes an illumination position for generating a light beam, a first receiver for measuring the intensity (I) or (Ip) of a light beam scattered by floating particles in a detection zone, a second receiver for measuring the intensity (Is) of a polarized light beam in a direction perpendicular to light illuminated by the light beam and means for measuring the degree of polarization of the particles for distinguishing pollen particles from other particles.

The invention relates to a sun vector resolving method based on a compound eye simulated multi-channel polarization sensor. The sun vector resolving method comprises the following steps: at first, designing a structure model of the compound eye simulated multi-channel polarization sensor; then designing the selection criterion of the degree of polarization, acquiring the degree of polarization information of observed points in sky by using the multi-channel polarization sensor, and selecting the degree of polarization measurement values of a certain amount according to the selection criterion,taking three values from the degree of polarization measurement values as a set of resolving inputs and determining the weight of the set of resolving inputs; next, establishing the geometrical relationship with sun vectors according to each channel mounting matrix, establishing the constrained relationship with all skylight maximal degree of polarization by measuring the degree of polarization to obtain a system of nonlinear equations; and at last, resolving corresponding sun vectors of the set of resolving inputs by the system of nonlinear equations, and resolving weighted average on the multiple groups of sun vectors, so as to resolve the sun vectors in a module system. The sun vector resolving method can be used in sunny and cloudless weather, can be applied in cloudy weather environment at the same time, and has high robustness and environmental suitability.

A light emitting device having a relatively simple configuration is provided that emits stable light having a plurality of wavelengths. The light emitting device 1 comprises, in sequence, a composite substrate 3 and a gallium nitride-based semiconductor layer 5 including a light emitting layer 9. The composite substrate 3 includes a base 19 and a gallium nitride layer, the gallium nitride-based semiconductor layer 5 being disposed on a principal surface of the gallium nitride layer, the angle θ defined by the c-axis of the gallium nitride layer and a normal line N1 to the principal surface S1 of the gallium nitride layer ranging from 50 to 130 degrees, the light emitting layer 9 emitting light with an absolute value of the degree of polarization of 0.2 or more, the base 19 containing a fluorescent material that emits a fluorescent light component induced by irradiation of a light component emitted from the light emitting layer 9. Accordingly, the light emitting device 1 can emit white light produced by superposition of blue light directly emitted from the light emitting layer 9 and yellow light induced by blue light incident on the base 19 from the light emitting layer 9.