85 results about "Spectral shift" patented technology

Light is coupled into two polarization modes of a waveguide, e.g., an optical fiber. The spectral response of Rayleigh backscatter in the waveguide segment for the two polarization modes is measured, e.g., using OFDR, OTDR, OLCR, etc. The autocorrelation of the spectral response is calculated. The spectral (wavelength) shift from a main autocorrelation peak to a side autocorrelation peak, corresponding to one of the two polarization modes of the waveguide segment, is determined. The spectral shift, corresponding to a beat length of the waveguide segment, is multiplied by an average index of refraction to determine a birefringence of the waveguide segment.

Authenticating an authentic article having an authentication mark. Acquiring a set of spectral images of the authentication mark, for forming a set of single-authentication mark spectral fingerprint data (FIG. 1). Identifying at least one spectral shift in the set of single-authentication mark spectral fingerprint data, for forming an intra-authentication mark physicochemical region group including sub-sets of intra-authentication mark spectral fingerprint pattern data, such that data elements in each sub-set are shifted relative to corresponding data elements in remaining sub-sets in the same intra-authentication mark physicochemical region group (FIG. 2). Forming a set of intra-authentication mark physicochemical properties and characteristics data relating to the imaged authentication mark, by performing pattern recognition and classification analysis on the intra-authentication mark physicochemical region group (FIG. 3). Comparing and matching elements in the set of intra-authentication mark physicochemical properties and characteristics data to corresponding reference elements in reference set of data, thereby authenticating the authentic article.

This invention discloses a projection screen including a diffusion layer, a cap layer, an interference layer and an absorption layer. The projection screen of this invention is based on the concept of inverse reflection. The interference filter includes a plurality of high and low refractive index layers, both of which alternately stacked. The projection screen conveys a small spectral shift and a narrow bandwidth at different incident angles so that the better contract ratio of the image signal can be displayed.

The invention presents a tube core shape design with high luminous efficiency, which comprises: epitaxial growing on island area LED chip with discrete grain; after laser peeling, packaging discrete chip into LED with vertical structure and high luminous efficiency. Wherein, the epitaxial growth improves crystal quality and internal quantum efficiency; the shape of island area increases LED light power; the island growth benefits to release stress, reduce stress on interface between GaN and sapphire substrate and the damage and spectral shift during peeling, thereby, it can obtain LED with high performance.

Silicon Carbide (SiC) probe designs for extreme temperature and pressure sensing uses a single crystal SiC optical chip encased in a sintered SiC material probe. The SiC chip may be protected for high temperature only use or exposed for both temperature and pressure sensing. Hybrid signal processing techniques allow fault-tolerant extreme temperature sensing. Wavelength peak-to-peak (or null-to-null) collective spectrum spread measurement to detect wavelength peak / null shift measurement forms a coarse-fine temperature measurement using broadband spectrum monitoring. The SiC probe frontend acts as a stable emissivity Black-body radiator and monitoring the shift in radiation spectrum enables a pyrometer. This application combines all-SiC pyrometry with thick SiC etalon laser interferometry within a free-spectral range to form a coarse-fine temperature measurement sensor. RF notch filtering techniques improve the sensitivity of the temperature measurement where fine spectral shift or spectrum measurements are needed to deduce temperature.

The present invention provides an optical sensor for monitoring current or power in a monitored element of a device such as a bridge-wire or hot-wire of electro-explosive devices. The optical sensor comprises an optical sensor made of semiconductor material. The semiconductor material comprises an absorption edge which is sensitive to a temperature variation. The semiconductor material is for placing in thermal contact with the monitored element of the device, whereby, when the current or power varies in the monitored element, it causes a variation in temperature in the semiconductor element and hence a spectral shift of the absorption edge which can be measured and which is representative of current and power variation.

Methods of making an integrated barrier stack and optical enhancement layer for protecting and improving the light out coupling of an encapsulated OLED are described. The method includes optimizing the thickness of various layers including the initial inorganic barrier layer and the inorganic barrier layer and polymeric decoupling layer for the barrier stack. The thickness is optimized for at least one of maximum efficiency, minimum dispersion, or minimum spectral shift so that the encapsulated OLED has enhanced light outcoupling compared to the bare OLED.

The invention relates to charged single-wall carbon nanotubes and their use in sensing and monitoring devices. The charged single-wall carbon nanotubes, have been found to have spectral shifts in certain regions of the electromagnetic spectrum. The charged single wall nanotubes are very sensitive to environmental perturbations and the nanotube's optical properties will be affected by these perturbations. Accordingly, the charged single wall carbon nanotubes can be used as sensors for a wide variety of applications, such as salt concentrations and pH, signal generators, measuring length of DNA molecules, as well as optical tags for biological detection and mapping of malignant cell activity. Optimal sensor devices are achieved in the present invention when the charged single-wall carbon nanotube carries a linear charge density close to that of DNA. The invention further describes an optical pH sensor comprising at least one charged carbon nanotube in solution.

A differential measurement system using pairs of Bragg gratings including at least one optical sensor having two Bragg gratings in two optical waveguides and having sensitivities adjusted so that respective spectra of the two gratings have a relative spectral shift dependent on a parameter or parameters to be measured. The system also includes an optical source to supply light to the two optical waveguides to interrogate them, a mechanism enabling light to pass successively through the two Bragg gratings of the same sensor, photodetectors to measure the power level of light having passed only through one of the two optical waveguides and the power level of light having passed successively through the two optical waveguides, and a processor to process the power levels and supply values of the parameter or parameters measured. The system is applicable in particular to measurements of temperatures, stresses, and pressures.

This system comprises at least one optical sensor (C1, C2, C3) comprising two Bragg gratings (B11, B12; B21, B22; B31, B32) written in two optical waveguides and having sensitivities adjusted so that the respective spectra of the two gratings have a relative spectral shift which depends on the parameter or parameters to be measured. The system also comprises an optical source (6) provided in order to supply light to the two optical waveguides so as to interrogate the latter, means enabling the light to pass successively through the two Bragg gratings of the same sensor, photodetectors in order to measure, on the one hand, the power level of light (R1) having passed only through one of the two optical waveguides and, on the other hand, the power level of light (R'1) having passed successively through the two optical waveguides, and means to process these power levels and supply the values of the parameter or parameters measured. The invention is applicable in particular to measurements of temperatures, stresses and pressures.

A method and a system for ultimately fast frequency-scanning Brillouin optical time domain analysis are provided herein. The method may include: simultaneously launching two pairs each having a pulsed pump wave and a counter-propagating constant wave (CW) probe wave, into an optical fiber, wherein the pulsed pumps have orthogonal States of Polarization (SOPs), and wherein the two CW probe waves have a same SOP; scanning common pump-probe frequency difference, over a frequency range that encompasses a respective Brillouin Gain Spectrum (BGS) and current and expected spectral shifts of the BGS along the optical fiber; deriving, a local Brillouin Frequency Shift (BFS), in a distributed manner along the optical fiber, which is defined as the pump-probe frequency difference which maximizes the Brillouin gain on the BGS; and determining strain and / or temperature in a distributed manner along the optical fiber, based on the respective local BFS.

Application: detection of binding of biological and / or chemical components of liquid or gaseous mixtures and solutions, which are of mainly biological origin and / or determine parameters of living activity of biological objects, to substances that bind the said components due to a biological, chemical or physical interaction; and analysis of mixtures and solutions to determine presence of biological and / or chemical components. Essence: binding substances are arranged on a surface of or inside a sensor layer, which changes its thickness due to the binding being detected; the layer is affected by light of different wavelengths; a signal due to interference on the sensor layer is registered in the reflected or transmitted light. In the first variant, the signal is represented by a spectrum; the sensor layer is more than 10 mum thick and exceeds the maximal recorded wavelength by at least an order of magnitude; information about the binding being detected is obtained from analysis of a spectral shift of interference maximums and minimums. In the second variant, the light passes also a scanned Fabry-Perot interferometer; the recorded signal is a dependence of intensity of the resulting light upon changes of base of the scanned Fabry-Perot interferometer, in which maximums due to correlation of the spectral characteristics of interaction of the light with the sensor layer and interferometer are observed; information about the binding being detected is obtained from a shift of the said dependence along values of base. In the third variant, other interferometers are used, which are scanned due to a change of the path difference of interfering beams. The required technical result is to make measurement results independent from uncontrollable variations of intensity of the analyzed light in whole as well as in any part of its spectrum, any areas of the sensor layer, and, consequently, to increase accuracy of measurements and reliability of results, sensitivity and resolution with simultaneous reduction of the number of necessary operations, of labor input and cost of both single- and multi-channel variants including real-time registration.

The invention relates to a method for measuring gas components and in particular relates to a method for correcting spectral shift in differential optical absorption spectroscopy (DOAS) measurement for measuring gas components with DOAS. In order to eliminate influence of offset on the differential absorption spectrum, the signal spectrum is subjected to offset correction; since the offset of the spectral line is possibly not the integer multiples of the measurement channel number, interpolation is required in the correction; and through interpolation re-sampling, the corrected signal spectrum after slight offset can be obtained. By adopting the method, the influence of the offset of the spectral line on the absorption spectrum is obviously reduced, and the influence on the fitting result of the final DOAS calculation is basically eliminated.