16results about "Correlation spectrometry" patented technology

A computer implemented method of determining a property of an unknown tobacco sample (26) comprising using hyperspectral imaging in combination with a machine-learning-based prediction framework. The method comprises: creating a first, reference spectral fingerprint dataset by scanning a plurality of known tobacco samples (26) using hyperspectral imaging techniques, generating hyperspectral images of each of said known tobacco samples and forming a reference spectral fingerprint, and storing each of said reference spectral fingerprints into said first, reference spectral fingerprint dataset. The method also comprises providing a second, known property, dataset, comprising known properties / compositions of said known tobacco sample, and inputting said first, reference spectral fingerprint dataset and said second, known property, dataset into said machine learning-based prediction framework. The method further comprises via said machine learning- based prediction framework, correlating said first, spectral fingerprint dataset with said known property or properties of said second, known property, dataset; said machine-learning based prediction framework generating a prediction model that is configured to determine one or more mathematical functions based on said first reference spectral fingerprint dataset, and said second, known property dataset. The method further comprises generating (100) hyperspectral images of said unknown tobacco sample (26), and based on said hyperspectral images of said unknown tobacco sample, generating a spectral fingerprint of said unknown tobacco sample. The method also comprises inputting said spectral fingerprint of said unknown tobacco sample into said machine learning-based prediction framework, and said machine-learning-based prediction framework applying said one or more mathematical functions to obtain and output said determined property of said unknown tobacco sample (26).

Method (100) of optical spectroscopy for analyzing a sample using an optical spectrometer (10), comprising: Obtaining a sample spectrum (101) of the sample using the optical spectrometer; Obtaining a blank spectrum (102) using the optical spectrometer, wherein the blank spectrum includes structured background radiation that correlates with the sample spectrum; Determining a cross-correlation (103) of the sample spectrum and the blank spectrum; Generating a mapped blind spectrum (105) by mapping the blind spectrum onto the sample spectrum based on cross-correlation; and Subtracting the imaged blank spectrum from the sample spectrum to produce a background-corrected sample spectrum (106).

An apparatus and a corresponding method for analyzing a laser process, the apparatus including a sensor module (100) configured to acquire an optical signal generated during a laser process of a target, and a processor (300) configured to detect an abnormality of the laser process through an instantaneous change analysis process of the optical signal performed whenever the optical signal is acquired by the sensor module (100), and a longitudinal change analysis process of the optical signal performed at a time point when a target time section ends, the target time section being a time during which the laser process is performed.

An apparatus for analyzing a laser process, the apparatus including a sensor module configured to acquire an optical signal generated during a laser process of a target, and a processor configured to detect an abnormality of the laser process through an instantaneous change analysis process of the optical signal performed whenever the optical signal is acquired by the sensor module, and a longitudinal change analysis process of the optical signal performed at a time point when a target time section ends, the target time section being a time during which the laser process is performed.

The invention provides an optical microcavity dispersion measurement method based on dispersion linetype real-time calibration, which is applied to the technical field of microcavity dispersion measurement, and comprises the following steps: converting the position extraction of an optical sideband into the position extraction of a dispersion linetype, and demodulating the optical sideband through a frequency mixer to obtain a sideband harmonic peak of a specific dispersion linetype; adjusting the phase difference between a modulation signal and a demodulation signal of the high-stability radio frequency source, identifying the position of a dispersion line type sideband harmonic peak, and extracting the frequency interval of the sideband harmonic peaks on the two sides of each resonance mode; dynamically calibrating the optical fiber Mach-Zehnder interferometer based on the number of sinusoidal signal cycles in the frequency interval of the dispersion line type sideband resonance peaks on the two sides of each resonance mode to obtain a calibrated Mach-Zehnder interferometer; and generating a dispersion measurement result of the optical microcavity according to the calibrated Mach-Zehnder interferometer interference signal. According to the invention, the dispersion measurement precision and the automation level can be improved.

A system comprising: a first light source; a second light source; a light combining apparatus; and a plurality of optical channels arranged to provide: a first sample path, wherein a first portion of the first sample path is arranged to couple the first light source to an object to be analysed, and wherein a second portion of the first sample path is arranged to couple the object to the light combining apparatus; a first reference path arranged to couple the first light source to the light combining apparatus; a second sample path, wherein a first portion of the second sample path is arranged to couple the second light source to the object, and wherein a second portion of the second sample path is arranged to couple the object to the light combining apparatus; and a second reference path arranged to couple the second light source to the light combining apparatus; wherein the light combining apparatus is configured to: combine sample light from the first light source received via the first sample path with reference light from the first light source received via the first reference path to provide a first plurality of beat frequency components; combine sample light from the second light source received via the second sample path with reference light from the second light source received via the second reference path to provide a second plurality of beat frequency components; and provide a combined optical signal comprising a sum of the first plurality of beat frequency components and the second plurality of beat frequency components; wherein the system is configured to overlap the first plurality of beat frequency components with the second plurality of beat frequency components in the combined optical signal such that distributions of time of flight through the object associated with the first and second plurality of beat frequency components are aligned in the time of flight dimension.

A beating spectroscopy device includes: first and second quantum cascade lasers; a quantum cascade detector; and a sample holder configured to hold a sample on an optical path between the second quantum cascade laser and the quantum cascade detector. Lights from the first and second quantum cascade lasers are detected by the quantum cascade detector while a wavelength of the light from the second quantum cascade laser is changed to scan a frequency of a beating signal having a frequency in accordance with a wavelength difference between the lights from the first and second quantum cascade lasers.

The DCS includes a pair of optical frequency combs (FC) which generate respective outputs at different pulse repetition frequencies (PRF) in a monitoring regime mode characterized by free running FCs. The outputs are combined in a single output which is split between sample-investigating (SI) and reference channels with the latter including a cell with etalon material which has a known etalon spectrum at low pressure. The etalon spectrum contains one or more broadly spaced apart, high intensity narrow molecular lines. Upon interacting with one of the beams, the cell emits a cell signal detected by a photodetector. The cell signal is processed in a data processing unit operative to mathematically filter out a single molecular line of the etalon spectrum and correct the phase change in the filtered line. The corrected phase change is used to restore the desired spectrum of the cell signal and further the desired spectrum of the SI signal.

To provide a wavelength dispersion measuring device that can accurately measure wavelength dispersion even in samples prone to exhibiting nonlinear optical phenomena. [Solution] The wavelength dispersion measuring device 1C comprises a light source 10, an optical pulse train generation unit 20, an optical amplifier 30, a measurement unit 40, a calculation unit 50, a spectrometer 60, and a control unit 70. The optical pulse train generation unit 20 generates an optical pulse train including a first optical pulse and a second optical pulse based on the optical pulses output from the light source 10. The spectrometer 60 measures the spectrum of the optical pulse train after it has been output from the optical pulse train generation unit 20 and passed through the optical amplifier 30. Based on the spectrum measured by the spectrometer 60, the control unit 70 controls the generation of the optical pulse train by the optical pulse train generation unit 20 so that the spectral shapes of the first optical pulse and the second optical pulse are symmetrical.

DCS analyzer including a memory to store autocorrelation values, model parameters, fitting parameters, and simulated correlation values from a DCS model; a mean square error (MSE) module to compute MSE between theoretical autocorrelation values computed from the model parameters and measured autocorrelation values; a sorting module to sort three latest MSE values obtained from the MSE module and generate indexes of largest, medium, and smallest MSE values; a convergence checking module to determine whether convergence is reached in solving an autocorrelation equation; a search module to calculate αDB and β values at reflection, extension, contraction, and shrink locations; a comparison module to compare two latest MSE values and find new αDB and β values to replace values associated with a largest MSE; a state controller coupled with the memory and the modules to control an operation thereof; and an output buffer to present a fitted solution of the autocorrelation equation.

The application discloses a spectrum detector, a spectrum instrument and a spectrum detection method. The spectrum detector comprises a tunable laser, a phase modulator, a 50:50 beam splitter, a first photodiode, a second photodiode, a transimpedance amplifier, a data acquisition module, a control module and a data processing module. The tunable laser is used as a local light source, and the control module and the phase modulator are added, so that the laser beam is coherently coupled with a to-be-detected light signal. The coherently coupled light beams are respectively incident into two similar photodiodes, and a photocurrent difference signal is generated at a series connection node of the two photodiodes. After processing the signal, intensity information of the amplified coherent signal is obtained. Then, the data processing module combines phase scanning information of the laser beam under different wavelengths, and wavelength and spectrum information of the to-be-detected light signal are obtained, so that efficient detection of a weak light beam or a single-photon-level light signal is realized.

A method of quantifying fluorescent dyes labeled on extracellular vesicles, including providing an extracellular vesicle molecule labeled with a fluorescence dye molecule, and determining a brightness of each of the extracellular vesicle molecule labeled with the fluorescence dye molecule and the fluorescence dye molecule through fluorescence correlation spectroscopy (FCS) of the extracellular vesicle molecule and the fluorescence dye molecule.

A method for adaptive dual frequency-comb spectroscopy includes repeatedly (i) recording a single interferogram with a dual frequency-comb spectrometer, (ii) averaging the single interferogram into an averaged interferogram, and (iii) determining a signal-to-noise ratio (SNR) of the averaged interferogram, until the SNR of the averaged interferogram exceeds a SNR threshold. In certain embodiments, determining the SNR includes determining a signal amplitude of a center burst of the averaged interferogram and determining a noise level of the averaged interferogram from data points of the averaged interferogram located away from the center burst. In certain embodiments, determining the SNR includes Fourier transforming the averaged interferogram into a frequency spectrum and numerically integrating the frequency spectrum.

A dispersion measurement apparatus includes a pulse forming unit, a correlation optical system, a photodetection unit, and an operation unit. The pulse forming unit forms a light pulse train including a plurality of light pulses having time differences and center wavelengths different from each other from a measurement target light pulse output from a pulsed laser light source. The correlation optical system receives the light pulse train output from the pulse forming unit and outputs correlation light including a cross-correlation or an autocorrelation of the light pulse train. The photodetection unit detects a temporal waveform of the correlation light output from the correlation optical system. The operation unit estimates a wavelength dispersion amount of the pulsed laser light source based on a feature value of the temporal waveform of the correlation light.

A decrease in accuracy caused by influence of noise light is suppressed. A spectroscopic device (1) includes a light source (2), a quantum optical system (4), a detection unit (6) that detects a light intensity of light output from the quantum optical system (4), and an analysis device (8), the quantum optical system (4) including one or more nonlinear optical elements (12) that generates a photon pair of idler light and signal light from the pump light in an entangled photon pair generation process, and a sample placement tool (35) that places a sample (SP) on an optical path of the idler light. The quantum optical system (4) is configured to emit first and second signal lights (s1, s2) along different optical paths, the detection unit (6) includes a beam splitter (40) that receives the first and second signal lights (s1, s2) from the quantum optical system (4), and detects a light intensity of each of two lights emitted from the beam splitter (40), and the analysis device (8) acquires an interferogram from the two lights detected by the detection unit (6).

Apparatus and methods for analyzing laser processes are provided. The apparatus comprises: a sensor module configured to acquire an optical signal generated during a laser process of a target; and a processor configured to detect an abnormality of the laser process by an instantaneous change analysis process of the optical signal performed each time the optical signal is acquired by the sensor module and a longitudinal change analysis process of the optical signal performed at a point in time at the end of the target time period, the target time period is a time during which the laser process is performed.