摘要:
A system and method are disclosed for gas sensing over a wide tunable wavelength range provided by one or more quantum cascade lasers. A laser beam is generated within the wide tunable wavelength range, which is given by the sum of the wavelength ranges from the individual lasers. Gas sensing or detection is achieved by obtaining an infrared absorption spectrum for a sample contained in one or more cells having different path lengths for the laser beam.
摘要:
According to various embodiments, a Raman spectroscopy method is provided for reduction of background fluorescence signal. The method may utilize a high speed optical chopper configured to periodically interrupt the laser light beam between the laser light source and the sample; and using the high speed optical chopper to provide a synchronized time-gated optical window for receiving mostly Raman signal while rejecting most or some of the fluorescence signal transmitted from the sample in response to the laser light beam before reaching the sensor
摘要:
Verfahren und Gasanalysator zur Messung der Konzentration einer Gaskomponente in einem Messgas Zur Messung der Konzentration einer Gaskomponente in einem Messgas (1), wird eine wellenlängenabstimmbare Laserdiode (3) mit einem Strom (i) angesteuert und das von der Laserdiode (3) erzeugte Licht (4) durch das Messgas (1) auf einen Detektor (5) geführt. Dabei wird der Strom (i) in periodisch aufeinanderfolgenden Abtastintervallen variiert, um eine interessierende Absorptionslinie der Gaskomponente wellenlängenabhängig abzutasten. Der Strom (i) kann zusätzlich im Sinne der Wellenlängenmodulationsspektroskopie mit geringer Frequenz und kleiner Amplitude sinusförmig moduliert werden. Ein von dem Detektor (5) erzeugtes Messsignal (14) wird zu einem Messergebnis (16) ausgewertet. Um das Messsignal-Rausch-Verhältnis zu verbessern und so bei gleicher Messstrecke eine deutlich niedrigere Nachweisgrenze zu erreichen, wird der Strom (i) mit mindestens einer hohen (HF-)Frequenz im GHz-Bereich moduliert, so dass keine Wellenlängenmodulation stattfindet. Die Amplitude der HF-Modulation wird unter Ausnutzung des linearen Aussteuerbereichs der Laserdiode (3) mit maximaler Höhe gewählt. Das Messsignal (14) wird vor seiner Auswertung an der Stelle der mindestens einen hohen Frequenz demoduliert.
摘要:
The present invention concerns a method for determining at least one absorption band in a spectrum, the method at least comprising the steps of: - providing a measured absorption spectrum from the sample, - providing a calculation spectrum, - from the calculation spectrum, extracting at least one absorption band, - calculating a residual spectrum by removing each extracted absorption band from the calculation spectrum, - testing whether a predefined stop criterion is fulfilled by the residual spectrum, - if the stop criterion is not fulfilled, using the residual spectrum as the calculation spectrum and iterating the extracting step, the forming step, the calculating step and the testing step, and - if the stop criterion is fulfilled, outputting each extracted absorption band.
摘要:
A method of stabilizing output signals from a cascade optical detector in an optical spectroscopy apparatus, particularly a reflectance anisotropy spectroscopy apparatus, and generating a stable output photocurrent signal from the optical detector by controlling the supply voltage to the detector in constant photocurrent mode, wherein control is performed at a relatively low voltage, i.e. lower than 10 V.
摘要:
A system and method are disclosed for configuring an integrated computational element (ICE) to measure a property of a sample of interest. The system includes an illumination source to provide a sample light which is reflected from or transmitted through a sample. A dispersive element disperses the sample light into wavelength portions. An intensity modulation device having an array of electronically controllable modulation elements is disclosed that forms a pattern which modulates the dispersed sample light. Collection optics focuses the modulated sample light on a detector, which generates a signal that correlates to a property of the sample. The electronically controllable modulation elements can be readily altered to conform to a different measurable property of a sample of interest as desired.
摘要:
Die Erfindung betrifft eine Vorrichtung zur Aufnahme eines Absorptionsspektrums eines Fluids mit einer ersten Strahlungsquelle (1), die entlang eines ersten Strahlengangs (11) eine Strahlung in einem ersten Spektralbereich emittiert, mit einer in dem ersten Strahlengang (11) angeordneten ersten Messstrecke (5), entlang derer die Strahlung durch das Fluid tritt, mit einem in dem ersten Strahlengang (11) angeordneten durchstimmbaren Fabry-Perot Interferometer (7), das als ein verschiebbarer Bandpassfilter Strahlung in dem ersten Spektralbereich transmittieren kann, und mit einem ersten Detektor (9; 35) zur Messung der Intensität der Strahlung in dem ersten Spektralbereich. Erfindungsgemäß ist vorgesehen, dass die Vorrichtung ein erstes Etalon (3) zur spektralen Modulation der Strahlung aufweist, das in dem ersten Strahlengang (11) angeordnet ist und das in dem ersten Spektralbereich eine Mehrzahl von Transmissionsmaxima (17) aufweist, und dass das Fabry- Perot (7) dazu eingerichtet ist, dass das von dem Fabry-Perot Interferometer (7) gebildete Bandpassfilter derart über den ersten Spektralbereich verschoben werden kann, dass die spektrale Modulation der Strahlung durch das erste Etalon (3) als eine zeitliche Modulation der Intensität der Strahlung von dem ersten Detektor (9, 35) gemessen werden kann.
摘要:
A method is provided comprising, obtaining an infrared (IR) spectrum of a Peripheral Blood Mononuclear Cells (PBMC) sample by analyzing the sample by infrared spectroscopy; and based on the infrared spectrum, generating an output indicative of the presence of a solid tumor or a pre-malignant condition. Other embodiments are also provided.
摘要:
A method and an apparatus for carrying out a chemical-physical analysis, such as a spectroscopic analysis, an absorption analysis, a scattering analysis, etc. on one or more regions of a sample (11 ), provides prearranging a source (1 ) of a first electromagnetic radiation comprising a plurality of components with respective wavelength, prearranging a plurality of sites (9) distributed on a determined surface to emit the first radiation, arranging such surface facing a corresponding region of a sample (11 ) such that the whole surface thereof is attained by the first radiation, emitting the first radiation on the sample (11) thus causing the emission of a second radiation by the sample (11 ), which is analysed to associate an intensity of the second radiation to each region and wavelength. For each of the wavelength of the first radiation, a wavelength code is selected by which respective components of the first radiation are coded; the coded components are joined together to form the first electromagnetic radiation which is distributed in a plurality of radiation beams. Such beams are conveyed to respective emission sites (9), for each of which an emission site (9) code is selected, a radiation beam being codified by said code. A decoding of the of the second radiation produces a plurality of fractions, each fraction associated to a wavelength of the first radiation such that for each emission site (9) it is possible to instantaneously compare each fraction associated to a respective wavelength with a component of the first radiation having the same wavelength, the components of the first electromagnetic radiation being emitted simultaneously. The steps of wavelength coding and of site coding, and possibly also other coding steps may be earned out subsequently with respect to one another, or at the same time. The method and the apparatus allow reducing the time required to carry out said analysis.
摘要:
The present invention discloses a flow cell optical detection system comprising a light source, a flow cell and a light detector, wherein the light detector is arranged in a separate detector unit that is arranged to be releasably attached to a detector interface, the detector interface being in optical communication with the light source and comprises optical connectors for optically connecting the flow cell and the detector unit in the light path from the light source, and wherein the flow cell is an interchangeable unit arranged to be held in position by the detector unit when attached to the detector interface.