Abstract:
A method of Raman detection for a portable, integrated spectrometer instrument includes directing Raman scattered photons by a sample to an avalanche photodiode (APD), the APD configured to generate an output signal responsive to the intensity of the Raman scattered photons incident thereon. The output signal of the APD is amplified and passed through a discriminator so as to reject at least one or more of amplifier noise and dark noise. A number of discrete output pulses within a set operational range of the discriminator is counted so as to determine a number of photons detected by the APD.
Abstract:
A colour measuring unit (1) comprising a radiation device (2) which emits light onto a surface (9) to be examined, wherein the radiation device (2) comprises at least one semiconductor-based light source (6), and a radiation detector device (12) which receives at least a portion of the light scattered by the surface and outputs a signal characteristic of this light, wherein the radiation detector device (12) allows a spectral analysis of the light impinging thereon. According to the invention, the colour measuring unit comprises at least one sensor device (10) which determines at least one electrical parameter of the light source (6), and also a processor device (14) which outputs from this measured parameter at least one value characteristic of the light emitted by the radiation device (2).
Abstract:
An analysis system, tool, and method for performing downhole fluid analysis, such as within a wellbore. The analysis system, tool, and method provide for a tool including a spectroscope for use in downhole fluid analysis which utilizes an adaptive optical element such as a Micro Mirror Array (MMA) and two distinct light channels and detectors to provide real-time scaling or normalization.
Abstract:
In a multi-wavelength spectroscopic apparatus using diffraction gratings, a first diffraction grating is a diffraction grating with diffraction efficiencies of p-polarized light and s-polarized light being equal on a short wavelength side of an operating wavelength range, and a second diffraction grating is a diffraction grating with diffraction efficiencies of p-polarized light and s-polarized light being equal on a long wavelength side of an operating wavelength range. By performing dispersion with two such diffraction gratings, it is possible to enlarge the amount of angular dispersion, and to produce a spectroscopic apparatus, which cancels wavelength dependencies of the diffraction efficiencies and has a small wavelength dependency of the diffraction efficiency.
Abstract:
A system and method for correction of instrument response of an optical spectroscopy instrument using a Raman standard sample supplied by NIST (National Institute of Standards and Technology). The smoother side of the NIST sample is placed facing a light collection optics in the spectroscopy instrument, whereas the non-smooth or rough side remains away from the light collection optics, but in contact with a platform or sample placement surface in the spectroscopy instrument. An instrument response function is determined with the NIST sample so placed. Thereafter, spectra or spectral images of target samples obtained using the spectroscopy instrument are divided by the instrument response function to correct for imperfections in the response of the optical spectroscopy instrument. The target sample spectra may be non-Raman spectra. The optical spectroscopy instrument may be a gratings-based or a tunable filter based chemical imaging system.
Abstract:
In a multi-wavelength spectroscopic apparatus using diffraction gratings, a first diffraction grating is a diffraction grating with diffraction efficiencies of p-polarized light and s-polarized light being equal on a short wavelength side of an operating wavelength range, and a second diffraction grating is a diffraction grating with diffraction efficiencies of p-polarized light and s-polarized light being equal on a long wavelength side of an operating wavelength range. By performing dispersion with two such diffraction gratings, it is possible to enlarge the amount of angular dispersion, and to produce a spectroscopic apparatus, which cancels wavelength dependencies of the diffraction efficiencies and has a small wavelength dependency of the diffraction efficiency.
Abstract:
A photodiode array for entering incident light a spectroscope device equipped with a wavelength dispersion element and detecting light emanating from the spectroscope device. The arrangement of each of photodiode elements constituting the photodiode array is displaced.
Abstract:
A method for producing a standard Raman spectrum of a sample. A source of incident radiation is provided. Means provide an incident beam and a monitor beam from the incident radiation. The incident beam is directed to the sample and a Raman beam is generated from the sample. Spectral data may be collected directly from the monitor beam and the Raman beam simultaneously. The occurrence of a frequency shift in the incident radiation is determined. One spectral measurement is made after the occurrence of the frequency shift, or a first spectral measurement is made before and a second spectral measurement is made after the frequency shift. One or more arithmetic calculations are applied to the single spectral measurement, or the second spectral measurement is subtracted from the first spectral measurement. One or more integral transforms are applied to the resulting spectral measurement data to produce the standard Raman spectrum.
Abstract:
An on-line scanning sensor system includes first and second horizontally extending guide members connected by side members to define a rigid box-like frame, and a support structure for suspending the box-like frame via vibration-absorbing devices such that vibrations are substantially attenuated before reaching the guide members. Further, the system includes a carriage mounted on the first guide member for scanning motion across a traveling web of sheet of material, and interferometer components mounted to the carriage for splitting and recombining infrared light and for directing a collimated beam of the recombined light onto the traveling sheet. Still further, the system includes a detector for receiving light from the interferometer components during scanning.
Abstract:
A method of performing color calibration of a multispectral image sensor (MIS) includes obtaining test measurement data of at least one color chart that is measured by a test MIS under at least one lighting environment, obtaining reference measurement data of the at least one color chart that is measured by a reference MIS under the at least one lighting environment, the reference MIS being calibrated in advance, and generating, based on the test measurement data and the reference measurement data, at least one transformation model configured to transform measurements between the test MIS and the reference MIS.