Abstract: Raw data inputs are treated as independent signal sources to reduce computational lag without adversely affecting signal-to-noise ratio (SNR). Applications include spectroscopy, multiple linear regression, mass balance quantitation and the calculation of physical properties. The input-specific averaging has been applied to Raman spectroscopy, where the inputs are averaged spectra from which peak heights or areas are obtained from integration. Alternatively, peak areas or heights can be obtained from unaveraged spectra and are then averaged before use in further calculations as inputs to produce a desired output. The output(s) are linear or nonlinear combinations of the peak heights or areas, coupled with weighting factors which relate the raw inputs to a quantitative output such as concentration of a chemical species. Each specific input can use a different type of averaging. The overall goal may be optimization for best precision, and/or optimization for minimum lag time.

Abstract: Methods and apparatus facilitate dynamic range balancing for multi-component peaks of widely varying magnitude in an optical spectrometer. In a specific embodiment, filters attenuate the C—H stretch region to produce a better fit of a multi-component hydrocarbon Raman spectrum to the dynamic range of a CCD detector. The filter may be translated into and out of the collimated collection beam to achieve a varying degree of attenuation. In certain applications, the filter is insertable into a collimated collection beam within a fiber-optic probe head to collect Raman spectra. The invention may include optical elements to create the collimated collection beam if not already present or not suitable for insertion of the filter. A second filter, an “opaque” or neutral density filter, may be insertable into the collimated collection beam to attenuate a broad spectral response within and outside the spectral range.

Abstract: Methods and apparatus facilitate dynamic range balancing for multi-component peaks of widely varying magnitude in an optical spectrometer. In a specific embodiment, filters attenuate the C—H stretch region to produce a better fit of a multi-component hydrocarbon Raman spectrum to the dynamic range of a CCD detector. The filter may be translated into and out of the collimated collection beam to achieve a varying degree of attenuation. In certain applications, the filter is insertable into a collimated collection beam within a fiber-optic probe head to collect Raman spectra. The invention may include optical elements to create the collimated collection beam if not already present or not suitable for insertion of the filter. A second filter, an “opaque” or neutral density filter, may be insertable into the collimated collection beam to attenuate a broad spectral response within and outside the spectral range.

Abstract: A material which is generally transparent in the visible region of the spectrum but reflective at laser wavelengths reduces undesirable, substrate-induced Raman and fluorescence scattering. A substrate provides a surface for supporting the sample, with the material being disposed between the surface of the substrate and the sample. The material is substantially transparent in the visible region of the spectrum but reflective at the laser wavelength, thereby minimizing unwanted Raman or fluorescence scattering that would be produced by the substrate if the material were not present. The substrate will typically be a glass microscope slide or multi-cell well plate. The optical filter material is preferably a multilayer dielectric filter acting as a “hot mirror” that reflects near-infrared energy. An advantage of visible transmission is that it allows back illumination from behind/underneath the slide or well plate, thereby being visible to a microscope's eyepiece or video camera.

Abstract: A material which is generally transparent in the visible region of the spectrum but reflective at laser wavelengths reduces undesirable, substrate-induced Raman and fluorescence scattering. A substrate provides a surface for supporting the sample, with the material being disposed between the surface of the substrate and the sample. The material is substantially transparent in the visible region of the spectrum but reflective at the laser wavelength, thereby minimizing unwanted Raman or fluorescence scattering that would be produced by the substrate if the material were not present. The substrate will typically be a glass microscope slide or multi-cell well plate. The optical filter material is preferably a multilayer dielectric filter acting as a “hot mirror” that reflects near-infrared energy. An advantage of visible transmission is that it allows back illumination from behind/underneath the slide or well plate, thereby being visible to a microscope's eyepiece or video camera.

Abstract: A material which is generally transparent in the visible region of the spectrum but reflective at laser wavelengths reduces undesirable, substrate-induced Raman and fluorescence scattering. A substrate provides a surface for supporting the sample, with the material being disposed between the surface of the substrate and the sample. The material is substantially transparent in the visible region of the spectrum but reflective at the laser wavelength, thereby minimizing unwanted Raman or fluorescence scattering that would be produced by the substrate if the material were not present. The substrate will typically be a glass microscope slide or multi-cell well plate. The optical filter material is preferably a multilayer dielectric filter acting as a “hot mirror” that reflects near-infrared energy. An advantage of visible transmission is that it allows back illumination from behind/underneath the slide or well plate, thereby being visible to a microscope's eyepiece or video camera.

Abstract: A material which is generally transparent in the visible region of the spectrum but reflective at laser wavelengths reduces undesirable, substrate-induced Raman and fluorescence scattering. A substrate provides a surface for supporting the sample, with the material being disposed between the surface of the substrate and the sample. The material is substantially transparent in the visible region of the spectrum but reflective at the laser wavelength, thereby minimizing unwanted Raman or fluorescence scattering that would be produced by the substrate if the material were not present. The substrate will typically be a glass microscope slide or multi-cell well plate. The optical filter material is preferably a multilayer dielectric filter acting as a “hot mirror” that reflects near-infrared energy. An advantage of visible transmission is that it allows back illumination from behind/underneath the slide or well plate, thereby being visible to a microscope's eyepiece or video camera.

Abstract: A multi-channel, reconfigurable fiber-coupled Raman instrument uses fiber optic switches for laser and calibration light routing to facilitate automated calibration, diagnosis and operational safety. The system allows wavelength axis calibration on all channels; laser wavelength calibration (including multiple and/or backup laser options); fiber coupling optimization; fault detection/diagnosis; and CCD camera binning setup. In the preferred embodiment, dedicated calibration channels surround data channels on a 2-dimensional CCD dispersed slit image implemented using a unique cabling architecture. This “over/under” calibration interpolation approach facilitates quasi-simultaneous or sequential calibration/data acquisitions. CCD binning between sequential calibration and data acquisitions enables higher density multi-channel operation with tilted images based upon a multiplexed grating configuration.

Abstract: A head-up display which combines an internal image, produced by a cathode ray tube image source, at substantially a wavelength of light .lambda., with an external image, using a holographic optical element. The holographic optical element consists of two or more holographic optical subelements in series, each satisfying the Bragg condition with respect to wavefronts at the wavelength .lambda. from a particular direction. While wavefronts satisfying these conditions are reflected to the observer's field of view, all others are transmitted through the holographic subelements. The holographic optical subelements largely overlap in the direction of their illumination by the internal image source, and may slightly overlap in the direction their images are to be presented to the observer. Wavelength .lambda. is chosen at the peak of the phosphor response curve of the cathode ray tube image source.