Abstract: A calibration reference for a multipass Raman analysis system, wherein a combination excitation and collection beam passes through a focal point F0 within a sample volume multiple times, is provided. The calibration reference includes a body of material having a known spectral response when illuminated by the combination excitation and collection beam. The size or shape of the body is selected or modified to keep the focal point at F0 within the body when the body is positioned within the sample volume for calibration purposes.

Abstract: An optical measurement probe for capturing a spectral response through an intervening material emitting unwanted background radiation includes: a first lens configured to receive light and collimate the light into a collimated excitation beam defining a first aperture; an objective element for focusing the collimated excitation beam to a point or region in a sample through the intervening material, wherein the objective element also receives light scattered by the sample and the intervening material and collimates the scattered light into a collimated collection beam defining a second aperture; and a blocking element within the collimated collection beam for removing the light scattered by the intervening material from the collimated collection beam received from the sample, wherein the second aperture defined by the collimated collection beam is at least two times greater than the first aperture defined by the collimated excitation beam.

Abstract: The present disclosure includes discloses a method for analyzing a multi-component gas sample using spectroscopy in combination with the measurement of extrinsic or intrinsic properties of the gas sample. The results of the spectroscopic analysis and the measurement are combined to quantify a gas component unseen by the spectroscopic analysis.

Abstract: An optical measurement probe for capturing a spectral response through an intervening material emitting unwanted background radiation includes: a first lens configured to receive light and collimate the light into a collimated excitation beam defining a first aperture; an objective element for focusing the collimated excitation beam to a point or region in a sample through the intervening material, wherein the objective element also receives light scattered by the sample and the intervening material and collimates the scattered light into a collimated collection beam defining a second aperture; and a blocking element within the collimated collection beam for removing the light scattered by the intervening material from the collimated collection beam received from the sample, wherein the second aperture defined by the collimated collection beam is at least two times greater than the first aperture defined by the collimated excitation beam.

Abstract: A method for harmonizing the responses of a plurality of Raman analyzers includes steps of calibrating an intensity axis response of a spectrometer to a reference light source and measuring a laser wavelength of a laser using the spectrometer. The method also includes steps of measuring a fluorescence spectrum induced by the laser at the laser wavelength of a plurality of standard reference material samples using the spectrometer, measuring a temperature of each standard reference material sample while measuring the fluorescence spectrum, and correcting the fluorescence spectrum of each standard reference material sample based on the respective temperature. The method further includes steps of deploying each standard reference material sample in one of a plurality of field calibrator devices and calibrating the intensity axis of one of the Raman analyzers using one of the field calibrator devices and the corrected fluorescence spectrum of the respective standard reference material sample.

Abstract: A method for harmonizing the responses of a plurality of Raman analyzers includes steps of calibrating an intensity axis response of a spectrometer to a reference light source and measuring a laser wavelength of a laser using the spectrometer. The method also includes steps of measuring a fluorescence spectrum induced by the laser at the laser wavelength of a plurality of standard reference material samples using the spectrometer, measuring a temperature of each standard reference material sample while measuring the fluorescence spectrum, and correcting the fluorescence spectrum of each standard reference material sample based on the respective temperature. The method further includes steps of deploying each standard reference material sample in one of a plurality of field calibrator devices and calibrating the intensity axis of one of the Raman analyzers using one of the field calibrator devices and the corrected fluorescence spectrum of the respective standard reference material sample.

Abstract: The effective coherence length of a single-frequency, solid-state laser is limited to reduce spurious, secondary holograms in conjunction with a holographic recording. The wavelength of the laser is varied or ‘scanned’ with high precision over a very small wavelength range. In an embodiment, the temperature of the laser's resonant cavity optical bench is altered, causing the dimension of the cavity to change and the emission wavelength to move in a controlled manner. The changing wavelength is monitored at high resolution, and a feedback control loop updates the temperature set-point to keep the monitored laser wavelength moving at a desired rate of change through a desired range. As the wavelength of the laser is scanned, the phase of the holographic interference pattern is locked at a position of maximum coherence/contrast within the holographic film aperture.

Abstract: The present disclosure includes discloses a method for analyzing a multi-component gas sample using spectroscopy in combination with the measurement of extrinsic or intrinsic properties of the gas sample. The results of the spectroscopic analysis and the measurement are combined to quantify a gas component unseen by the spectroscopic analysis.

Abstract: The present disclosure includes discloses a method for analyzing a multi-component gas sample using spectroscopy in combination with the measurement of extrinsic or intrinsic properties of the gas sample. The results of the spectroscopic analysis and the measurement are combined to quantify a gas component unseen by the spectroscopic analysis.

Abstract: A radiation shield for near-infrared detectors of the type used in Raman spectroscopic systems comprises a chamber enclosing the detector and a cooling device in thermal contact with the chamber and the detector to reduce the level of unwanted radiation to which the detector would otherwise be exposed. The chamber may include a window in optical alignment with the detector, and the window may include one or more coatings to pass wavelengths in a range of interest or block radiation at wavelengths outside of this range. The shield may be enclosed in an evacuated dewar having a window which may also include one or more coatings to favor the wavelength range.

Abstract: An apparatus for providing an optical display includes an optical substrate for propagating light received from a light source, a first set of one or more switchable diffractive elements in the substrate, and a second set of one or more switchable diffractive elements in the substrate. Each diffractive element in the second set corresponds to a diffractive element in the first set. Each of the diffractive elements in the first and second sets is configured to switch between on and off states. One of the states is for diffracting light and the other state for allowing light to pass through. Each of the first set of diffractive elements is configured to diffract the light at an angle for propagation in the substrate. Each of the second set of diffractive elements is configured to diffract the light for display.

Abstract: In one aspect of the present disclosure, improved end optics are disclosed that maximize the numerical aperture focused at a sample point while minimizing unwanted artifacts such as vignetting. The configurations also maintain centering of the excitation/collection beam on the objective if the probe tilts or bends. The disclosed configurations are particularly suited to probes wherein the excitation and/or collection paths between the probe and the laser/analyzer are coupled through multimode fibers, such as in Raman and other forms of laser spectroscopy. The disclosure includes the insertion of one or more additional lenses between the probe head and the focusing objective at the probe tip.

Abstract: The present disclosure includes discloses a method for analyzing a multi-component gas sample using spectroscopy in combination with the measurement of extrinsic or intrinsic properties of the gas sample. The results of the spectroscopic analysis and the measurement are combined to quantify a gas component unseen by the spectroscopic analysis.

Abstract: Systems and methods are used to couple an optical sampling probe to a port in a single-use bioreactor bag for in-process monitoring. A combination of re-useable and disposable components maintain precision while reducing costs. A disposable barb with an integral window, received by the port of the reaction vessel, is coupled to a re-useable optic component with a focusing lens. A separate focus alignment tool is used to set the lens position to a precise focal point before placement of the optic component into the barb. The fixture includes a window to simulate the window in a barb component, a target with a known spectral signature, and a probe head coupled to a spectral analyzer. The axial position of the lens is adjusted with respect to the spacer component to maximize the spectral signature from a sample target, whereupon the spacer component is bonded to the lens mount.

Abstract: Methods and systems for spectrometer dark correction are described which achieve more stable baselines, especially towards the edges where intensity correction magnifies any non-zero results of dark subtraction, and changes in dark current due to changes in temperature of the camera window frame are typically more pronounced. The resulting induced curvature of the baseline makes quantitation difficult in these regions. Use of the invention may provide metrics for the identification of system failure states such as loss of camera vacuum seal, drift in the temperature stabilization, and light leaks. In system aspects of the invention, a processor receives signals from a light detector in the spectrometer and executes software programs to calculate spectral responses, sum or average results, and perform other operations necessary to carry out the disclosed methods. In most preferred embodiments, the light signals received from a sample are used for Raman analysis.

Abstract: The present disclosure relates to assistive mechanisms and methods that aid an operator of a spectrometer to make spectral measurements of a sample, the measurements having a desired quality. The method enables quality spectral measurements quickly and simply, without a prior understanding of a sample's spectrum or of the details as to how the spectrum is measured. Data quality is improved, and the time required to collect the data is reduced. While a specific example of sample optic focus is disclosed in detail, the optimization of numerous other parameters is possible.

Abstract: The present disclosure relates to assistive mechanisms and methods that aid an operator of a spectrometer to make spectral measurements of a sample, the measurements having a desired quality. The method enables quality spectral measurements quickly and simply, without a prior understanding of a sample's spectrum or of the details as to how the spectrum is measured. Data quality is improved, and the time required to collect the data is reduced. While a specific example of sample optic focus is disclosed in detail, the optimization of numerous other parameters is possible.

Abstract: In one aspect of the present disclosure, improved end optics are disclosed that maximize the numerical aperture focused at a sample point while minimizing unwanted artifacts such as vignetting. The configurations also maintain centering of the excitation/collection beam on the objective if the probe tilts or bends. The disclosed configurations are particularly suited to probes wherein the excitation and/or collection paths between the probe and the laser/analyzer are coupled through multimode fibers, such as in Raman and other forms of laser spectroscopy. The disclosure includes the insertion of one or more additional lenses between the probe head and the focusing objective at the probe tip.

Abstract: Methods and systems for spectrometer dark correction are described which achieve more stable baselines, especially towards the edges where intensity correction magnifies any non-zero results of dark subtraction, and changes in dark current due to changes in temperature of the camera window frame are typically more pronounced. The resulting induced curvature of the baseline makes quantitation difficult in these regions. Use of the present disclosure may provide metrics for the identification of system failure states such as loss of camera vacuum seal, drift in the temperature stabilization, and light leaks. In system aspects of the present disclosure, a processor receives signals from a light detector in the spectrometer and executes software programs to calculate spectral responses, sum or average results, and perform other operations necessary to carry out the disclosed methods. In most preferred embodiments, the light signals received from a sample are used for Raman analysis.

Abstract: A radiation shield for near-infrared detectors of the type used in Raman spectroscopic systems comprises a chamber enclosing the detector and a cooling device in thermal contact with the chamber and the detector to reduce the level of unwanted radiation to which the detector would otherwise be exposed. The chamber may include a window in optical alignment with the detector, and the window may include one or more coatings to pass wavelengths in a range of interest or block radiation at wavelengths outside of this range. The shield may be enclosed in an evacuated dewar having a window which may also include one or more coatings to favor the wavelength range.