246 results about "Transmission spectroscopy" patented technology

Non-invasive, optical apparatus and methods for the direct measurement of hemoglobin derivatives and other analyte concentration levels in blood using diffuse reflection and transmission spectroscopy in the wavelength region 400-1350 nm which includes the transparent tissue window from approximately 610 to 1311 nanometers and, using diffuse reflection spectroscopy, the mid-infrared region from 4.3-12 microns in wavelength. Large area light collection techniques are utilized to provide a much larger pulsate signal than can be obtain with current sensor technology. Sensors used in separate or simultaneous precision measurements of both diffuse reflection and transmission, either separately or simultaneously, from pulsate, blood-perfused tissue for the subsequent determination of the blood analytes concentrations such as arterial blood oxygen saturation (SaO₂), carboxyhemoglobin (COHb), oxyhemoglobin (OHb), deoxyhemoglobin (dOHb), methemoglobin (metHb), water (H2O), hematocrit (HCT), glucose, cholesterol and proteins such as albumin and other analytes components.

A method and apparatus for performing refractive index, birefringence and optical activity measurements of a material such as a solid, liquid, gas or thin film is disclosed. The method and apparatus can also be used to measure the properties of a reflecting surface. The disclosed apparatus has an optical ring-resonator in the form of a fiber-loop resonator, or a race-track resonator, or any waveguide-ring or other structure with a closed optical path that constitutes a cavity. A sample is introduced into the optical path of the resonator such that the light in the resonator is transmitted through the sample and relative and/or absolute shifts of the resonance frequencies or changes of the characteristics of the transmission spectrum are observed. A change in the transfer characteristics of the resonant ring, such as a shift of the resonance frequency, is related to a sample's refractive index (refractive indices) and/or change thereof. In the case of birefringence measurements, rings that have modes with two (quasi)-orthogonal (linear or circular) polarization states are used to observe the relative shifts of the resonance frequencies. A reflecting surface may be introduced in a ring resonator. The reflecting surface can be raster-scanned for the purpose of height-profiling surface features. A surface plasmon resonance may be excited and phase changes of resonant light due to binding of analytes to the reflecting surface can be determined in the frequency domain.

Within a method of making an optical interference filter, sample spectra and measurements of a predetermined characteristic associated with respective spectra are provided. Upon selection of an initial number of filter layers and a thickness for each layer, a transmission spectrum is determined. Each sample spectrum is applied to a regression formula that relates interaction of light with the transmission spectrum to a regression value. A comparison relationship between the calculated regression values and the sample measurements is defined and optimized, wherein thickness of each layer is an optimization variable.

The present invention provides a method and apparatus for the detection of an infectious disease or disorder in a fluid, such as a mammalian blood sample, the detection of a specific protein in a urine sample, or the detection of a particle in a plasma. The identification of the particles of interest is enable by taking a transmission spectrum of a test sample in at least a portion of the ultraviolet, visible, near-infrared portion of the spectrum and comparing the spectrum with a standard sample spectrum. From the comparison it is then determined whether the fluid from the test sample contains an particle of interest, and an identity of the particle of interest is determined. Spectroscopic and multiwavelength turbidimetry techniques provide a rapid, inexpensive, and convenient means for diagnosis. The comparison and determination steps may be performed visually or by spectral deconvolution.

An image sensing system includes an IR notch filter configured to block transmission of spectral energy having wavelengths in an interface region between the visible and the invisible spectra and enable transmission of spectral energy having wavelengths in at least the visible spectrum and the near-infrared (IR) spectrum, a digital image sensor including a two-dimensional array of pixel elements and configured to generate output signals at each pixel element as pixel data representing an image of a scene, and a color filter array including a two-dimensional array of selectively transmissive filters superimposed on and in registration with the two-dimensional array of pixel elements. The color filter array includes a first group of selectively transmissive filters disposed to transmit spectral energy in one or more colors of the visible spectrum and a second group of gray color filters disposed to transmit spectral energy in at least the near-infrared (IR) spectrum.

A method and system for using transmission spectroscopy to measure a temperature of a substrate (135). By passing light through a substrate, the temperature of the substrate can be determined using the band-edge characteristics of the wafer. This in-situ method and system can be used as a feedback control in combination with a variable temperature substrate holder (182) to more accurately control the processing conditions of the substrate. By utilizing a multiplicity of measurement sites the variation of the temperature across the substrate (135) can also be measured.

In one embodiment of the invention, a transmitting spectral filter includes a thin film layer and a grating structure. The thin film layer is made of transmitting material to transmit a first incident radiation within a first band around a first wavelength. The first incident radiation is reflected from a mirror in an optical path. The grating structure is deposited on the thin film layer and is etched to have a grating period. The grating period causes transmission of the first incident radiation within the first band and causes at least one of reflection and diffraction of the second incident radiation above a second wavelength out of the optical path.

An imaging system includes an image sensor and an optical filter. The image sensor captures image data in response to incident light. The optical filter filters the light and includes a dual window transmission spectrum. The dual window transmission spectrum includes a first transmission window having a first pass band aligned to pass visible light and a second transmission window having a second pass band overlapping with an absorption band of infrared light in Earth's atmosphere.

The invention discloses a multispectral-based multipoint sampling multiparameter water quality on-line analytical system, comprising an optical system, a waterway system and a detection control system, wherein the optical system is used for scanning the ultraviolet-visible light transmitted spectrum, and fluorescence and Raman emission spectra and the like of a water sample to be detected by adopting a multi-wavelength laser, a pulsed xenon lamp and a charge coupled device (CCD) spectrum detector and converting the scanned spectra into digital signals; and based on multipoint sampling design, the waterway system is used for enabling quantified sewage and clear water to enter into a sampling device through controlling the on and off of a water pump and a solenoid valve so as to realize the collection of the spectroscopic data, moreover, the waterway system has a function of automatically cleaning a sewage pipeline system; and an industrial personal computer is adopted as a core processing unit of the detection control system. The whole system can automatically and continuously operate and is suitable for online analysis.

A VIS-NIR hyperspectral imaging filter has serial stages along an optical signal path with angularly distributed birefringent retarders and polarizers. The retarders can include active retarders such as tunable liquid crystal birefringent elements, passive retarders such as fixed retarders, and/or combinations thereof. Distinctly different periodic transmission spectra are provided by different filter stages, each having multiple retarders, in particular with some stages having broad bandpass peaks at wide spectral spacing and other stages have very narrow closely spaced peaks. The respective spectra include at least one tunably selectable band at which the transmission spectra of the filter stages coincide, whereby the salutary narrow bandpass and wide spectral spacing ranges of different stages apply together, resulting in a high finesse wavelength filter suitable for spectral imaging. The filter may be configured to provide faster switching speed and increased angle of acceptance and may operate in the rage of approximately 400-1100 nm.

The invention relates to refractometry and attenuated reflectance spectrometry in a wellbore environment. Specifically, it pertains to a robust apparatus and method for measuring refractive index of fluids along a continuum (rather than in steps), and for measuring attenuated reflectance spectra, and for interpreting the measurements made with this apparatus to determine a variety of formation fluid parameters. The present invention provides a method and apparatus to distinguish between gas and liquid based on the much lower index of refraction of gas. It can also be used to monitor fluid sample clean up over time. The refractive index of a wellbore fluid is determined from the fraction, R, of light reflected off the interface between a transparent window that has a known refractive index and this fluid. Preferably, the refractive index is measured at some wavelength of light for which the fluid is not highly attenuating but is optimally attenuating. The adjacent transmission spectrometer can be used to correct the refractive index measurement for attenuation at those wavelengths, which it monitors. Also, this reflection-based refractometer design can be used as an attenuated reflectance spectrometer at highly attenuating wavelengths.

The invention discloses a method and a device for carrying out identification of bank notes based on a spectrum analysis technique. The device comprises a light source, a bank-note passing channel, a monochromator, a photosensitive sensor, a signal amplifier and a digital processing unit, wherein a chromatic dispersion element in the monochromator is a diffraction grating, a prism, or an optical filter with a spectral resolution. The method comprises the following steps of: carrying out chromatic dispersion on reflected and transmitted light rays of a bank note by the monochromator; receiving the light intensity of each waveband by a receiving sensor so as to obtain reflected and transmitted spectral data of each waveband; carrying out relative analysis according to the data of a to-be-discriminated bank note and the data of a standard bank note, thereby obtaining relative coefficients; and discriminating whether the bank note is true and false according to the relative coefficients.

The invention discloses a quantum coherence effect-based antenna gain measuring device. The device comprises an electromagnetic wave absorbing chamber, an atomic gas chamber, a laser light source subsystem, a spectral signal measurement subsystem, a power measurement subsystem, an antenna gain measurement subsystem and a plurality of support platforms. According to the device disclosed by the invention, an optical device is used for triggering an energy spectrum, so that atoms are induced. An energy spectrum is obtained through photoelectric detection. Meanwhile, the wave-absorbing material isadopted to prevent an electromagnetic scattering body from affecting the measurement. Through measuring the feed-in net power of a measurement antenna and the net power of the coupling port of a directional coupler, the data acquisition of the transmitted spectrum of the detection light is completed. A power meter is connected with a computer through a GPIB bus, so that the reading of the feed-inpower value of the antenna is completed. Through an antenna gain measurement model (img file = 'DDA 0001510521350000011.T'wi = '355 'he = '170 '), the gain measurement is completed. Compared with a traditional antenna measuring system, the device has the advantages of high measurement precision, low construction cost, small occupied area and the like.

A SWIR hyperspectral imaging filter has serial stages along an optical signal path with angularly distributed birefringent retarders and polarizers. The retarders can include active retarders such as tunable liquid crystal birefringent elements, passive retarders such as fixed retarders, and/or combinations thereof. Distinctly different periodic transmission spectra are provided by different filter stages, each having multiple retarders, in particular with some stages having broad bandpass peaks at wide spectral spacing and other stages have very narrow closely spaced peaks. The respective spectra include at least one tunably selectable band at which the transmission spectra of the filter stages coincide, whereby the salutary narrow bandpass and wide spectral spacing ranges of different stages apply together, resulting in a high finesse wavelength filter suitable for spectral imaging. The filter may be configured to provide faster switching speed and increased angle of acceptance and may operate in the rage of approximately 850-1700 nm.

The invention discloses a transmission spectra based method and device for detecting oil product interfaces in oil pipelines. In the method, the light sent out by a light source module is divided into visible light, near near-infrared light, near-infrared light and intermediate infrared light, all the light irradiates on the flowing oil products by passing through incident optical fibers and collimated light components, then the transmitted light enters a spectrometer module by passing through condensation components and emergent optical fibers, the spectrometer module transfers the measured spectrum intensity data into a control module, after a computation module carries out computation according to the spectrum intensity data, the temperature data, the pressure data, the oil product flow velocity and the calibrated parameters in a calibrated parameter module, the data results are sent back to the control module and the control module sends the data results to a result output module to be displayed. The invention solves the problem of distinguishing the interfaces of the same kind of oil products with different trade names and the oil products with the same trade name but different properties; meanwhile, the invention also solves the problem of distinguishing the interfaces of the environment-friendly oil products and the common oil products.

The invention discloses a terahertz time-domain spectrograph capable of entering at a fixed angle and simultaneously detecting transmission and reflection and belongs to the technical field of spectrums. The spectrograph is characterized in that a femtosecond laser device is used as an excitation source, and a beam splitter arranged at the output end of the femtosecond laser device is used for splitting one beam of laser into two beams, wherein one beam is detection light; the other beam is further split into two beams through a beam splitting prism, wherein one beam is used as pumping light and the other beam is also used as the detection light; the pumping light is gathered on a terahertz transmitter and pulse terahertz waves are generated by radiation; the generated terahertz waves are used for irradiating a sample; the terahertz waves transmitting the sample are focused on one path of terahertz detector, and the terahertz waves reflected by the sample are focused on the other path of terahertz detector; the two paths of detection light are also focused on the two terahertz detectors at the same time, and pulse terahertz wave electric field amplitude values of transmission and reflection are calibrated. In the system, a relative position between a reflecting mirror and the sample is fixed, and a transmission spectrum and a reflection spectrum of the sample can be obtained at the same time, so that the transmittance and the reflectivity of the sample are accurately obtained, the reliability of data is guaranteed and experiment efficiency is also improved.

The invention relates to a Doppler laser radar device for measuring multiple meterological parameters, which comprises a transmitting system, a receiving system, a data acquisition system and a data processing computer, wherein the transmitting system comprises a pulse laser, a beam expander and a reflecting mirror; the receiving system comprises a telescope, an iodine filter, two photoelectric detectors and a light-dividing device; and the data acquisition system and the data processing computer are connected with the photoelectric detectors. The Doppler laser radar device is characterized in that the light-dividing device comprises six optical filter plates, and the light path position relation is as follows: atmospheric scattered light is projected onto the optical filter plate (a), and the reflected light of the optical filter plate (a) is vertically projected onto the optical filter plate (b); the transmitted light of the optical filter plate (a) is projected onto the optical filter plate (c) to the iodine filter; the reflected light of the optical filter plate (c) is projected onto the optical filter plate (d); the reflected light of the optical filter plate (d) is projected onto the optical filter plate (e); and the reflected light of the optical filter plate (e) is vertically projected onto the optical filter plate (f), and each transmitted light is received by the relative photoelectric detector. The invention can synchronously obtain atmospheric humidity, temperature, wind field and aerosol parameters within one-time light detection; and high cost and high consumption of multi-radar detection are obviously reduced.

The invention discloses a fruit sugar degree sorting device and method based on weighing and sorting line transformation. The fruit sugar degree sorting device and method based on the weighing and sorting line transformation comprises a mechanical conveying device, a visible near-infrared spectrum detection device and a sorting control device. Fruits are conveyed into the visible near-infrared spectrum detection device by the mechanical conveying device, a vertical light beam is used for irradiating the fruits to be detected. The light beam on the fruits reflects through the diffuse reflectionoptical principle, the visible near-infrared spectrum detection device use a visible near-infrared diffuse reflection spectrum to carry out on-line detection and classification for the sugars and acidity in the fruits, the detected sugars and acidity are transmitted to the sorting control device, and the sorting is achieved by turning over a fruit tray. By collecting the visible near-infrared diffuse reflection spectrum of the fruits in the wave band range of 300nm-1100nm and using a prediction model of predicting the sugars and acidity of the fruits, the content of sugars and acidity in thefruits is calculated, and the on-line detection and automatic sorting of the sugars and acidity are achieved in cooperation with a automatic control system.

The invention discloses a method and a device for testing the beat length of a polarization maintaining optical fiber, which establish a numerical model for the test of the beat length of the polarization maintaining optical fiber according to the spectrum modulation property of a transmission spectrum of a Sagnac interferometer consisting of an optical fiber coupler and a to-be-tested polarization maintaining optical fiber and the extreme point property of the transmission spectrum to test the wavelength difference between the adjacent extreme points of the transmission spectrum obtained by using a spectrum test device to realize the test of the beat length. The method and the device optimize the length parameters of the to-be-tested polarization maintaining optical fiber, establish a mathematical model for acquiring the optimal test length of the optical fiber and precisely test the beat length of the optical fiber at the optimal test length. The method for testing the beat length of the polarization maintaining optical fiber of the invention is simple in theory and achieves a precision of 0.01 millimeter of the beat length test performed at the optimal test length. The test device adopts a full optical fiber structure, and is low in cost, high in adaptability, strong in interference resisting capability and free from limitation on the beat length of the to-be-test optical fiber. The test method and the test device are suitable for the tests of beat lengths in various ranges of the polarization maintaining optical fibers. The device is simple in structure and convenient in operation.