Methods and Apparatus for Fluorescence Lifetime Imaging with Pulsed Light

    公开(公告)号:US20180259455A1

    公开(公告)日:2018-09-13

    申请号:US15487438

    申请日:2017-04-14

    Abstract: A light source may illuminate a scene with pulsed light that is pulsed non-periodically. The scene may include fluorescent material that fluoresces in response to the pulsed light. The pulsed light signal may comprise a maximum length sequence or Gold sequence. A lock-in time-of-flight sensor may take measurements of light returning from the scene. A computer may, for each pixel in the sensor, perform a Discrete Fourier Transform on measurements taken by the pixel, in order to calculate a vector of complex numbers for the pixel. Each complex number in the vector may encode phase and amplitude of incident light at the pixel and may correspond to measurements taken at a given time interval during the pulsed light signal. A computer may, based on phase of the complex numbers for a pixel, calculate fluorescence lifetime and scene depth of a scene point that corresponds to the pixel.

    MEASUREMENT OF HYDROCARBON FUEL GAS COMPOSITION AND PROPERTIES FROM TUNABLE DIODE LASER ABSORPTION SPECTROMETRY

    公开(公告)号:US20180095031A1

    公开(公告)日:2018-04-05

    申请号:US15283965

    申请日:2016-10-03

    Applicant: ABB Schweiz AG

    Abstract: A tunable diode laser absorption spectrometer and a method of processing absorption spectra is used to measure concentrations of selected fuel gas components and calculate several fuel gas parameters, including heating value, relative density, compressibility, theoretical hydrocarbon liquid content and Wobbe index. In the described incarnation, a tunable laser diode directs near-infrared light into an optical cavity through a sample of fuel gas. A sensor measures intensity of light exiting the cavity as the laser wavelength is tuned over a specified range to construct a cavity-enhanced absorption spectrum for the fuel gas. A set of basis spectra for expected component species is used to analyze the spectrum and determine component concentrations, including methane, ethane, carbon dioxide, and other discrete and structured absorbers. Critically, a generic broadband absorption is used to model higher hydrocarbons that present themselves as nearly featureless absorption spectra. The fuel gas parameters are then calculated directly from determined component concentrations and the broadband absorption representing the higher hydrocarbons.

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