Abstract:
A novel scanning monochromator uses a PM stepper-motor to directly drive a diffraction grating. By employing interpolated encoder feedback in combination with the PM stepper-motor feedback, a resolution of over 250,000 pulsed steps is available for each revolution of the PM stepper-motor. This translates into more than 20,000 incremental angular-displacement steps over a usable 30° range of dispersion-element rotation. High field accuracy is achieved by a direct PM stepper-driven diffraction grating, and a unique calibration approach based on Wood's anomalies. A plurality of diffracted light beams emerge from the oscillating grating, and these are scanned past a detector for detection, whereby the relative rotation information of the grating can be detected with great accuracy. A number of tolerance-correcting measures are also included to yield an extremely accurate, self-lubricating scanning monochromator that can be economically produced.
Abstract:
According to one aspect, an IR spectrometer includes a light source adapted to illuminate a sample, a grating adapted to spectrally disperse a light that has illuminated the sample, a MEMS array adapted to be electrostatically actuated by a controller to control a diffraction of the light, a detector configured to detect the light, and a power source adapted to supply power to the light source and to the MEMS array, wherein the controller is adapted to control the MEMS array so as to manage a power consumption of the IR spectrometer. In one embodiment, the IR spectrometer includes a housing sized and arranged to house the light source, the grating, the MEMS array, the controller, the detector, to and the power source in a hand-held device.
Abstract:
For spectrally filtering at least one input beam, a first reflective element is configured to tilt to multiple tilt orientations that each corresponds to a different angle of propagation of at least one input beam. One or more optical elements are configured to change at least some of the relative angles of propagation of the input beam for different tilt orientations of the first reflective element. A spectrally dispersive element is configured to receive the input beam at a location at which the central ray of the input beam is incident at different points on the spectrally dispersive element for each of the tilt orientations, and configured to disperse spectral components of the input beam at different respective angles in a spectral plane. The first reflective element is configured to tilt to select at least one and fewer than all of the dispersed spectral components to be directed to a selected output path.
Abstract:
A robust, compact spectrometer apparatus for determining respective concentrations or partial pressures of multiple gases in a gas sample with single as well as multiple and even overlapping, absorption or emission spectra that span a wide spectral range.
Abstract:
A novel scanning monochromator uses a PM stepper-motor to directly drive a diffraction grating. By employing interpolated encoder feedback in combination with the PM stepper-motor feedback, a resolution of over 250,000 pulsed steps is available for each revolution of the PM stepper-motor. This translates into more than 20,000 incremental angular-displacement steps over a usable 30° range of dispersion-element rotation. High field accuracy is achieved by a direct PM stepper-driven diffraction grating, and a unique calibration approach based on Wood's anomalies. A plurality of diffracted light beams emerge from the oscillating grating, and these are scanned past a detector for detection, whereby the relative rotation information of the grating can be detected with great accuracy. A number of tolerance-correcting measures are also included to yield an extremely accurate, self-lubricating scanning monochromator that can be economically produced.
Abstract:
A chemometric analyzer for analyzing a plurality of analytes. The analyzer disperses radiation by wavelength along an encoding axis. The analyzer includes a spatial radiation modulator having a plurality of radiation filters. Each radiation filter modulates the intensity of a corresponding spectral component in the radiation.
Abstract:
In one general aspect, a spectroscopic method for monitoring heterogeneity of a sample is disclosed. In this method, sampled spectroscopic measurements are acquired over a range of different micro locations in a macro-sample of the sample. This step is repeated for micro-locations in further macro-samples of the sample, and a statistical measure of chemical heterogeneity is derived from the acquisitions. In another general aspect, differently sized samples are acquired, and a statistical measure of chemical heterogeneity is derived from these acquisitions.
Abstract:
A novel scanning monochromator uses a PM stepper-motor to directly drive a diffraction grating. By employing interpolated encoder feedback in combination with the PM stepper-motor feedback, a resolution of over 250,000 pulsed steps is available for each revolution of the PM stepper-motor. This translates into more than 20,000 incremental angular-displacement steps over a usable 30° range of dispersion-element rotation. High field accuracy is achieved by a direct PM stepper-driven diffraction grating, and a unique calibration approach based on Wood's anomalies. A plurality of diffracted light beams emerge from the oscillating grating, and these are scanned past a detector for detection, whereby the relative rotation information of the grating can be detected with great accuracy. A number of tolerance-correcting measures are also included to yield an extremely accurate, self-lubricating scanning monochromator that can be economically produced.
Abstract:
A fluorescence spectrophotometer having an excitation double monochromator, a coaxial excitation/emission light transfer module, and an emission double monochromator. Each monochromator includes a pair of holographic concave gratings mounted to precisely select a desired band of wavelengths from incoming broadband light without using other optical elements, such as mirrors. Selected excitation light is directed into a sample well by a light transfer module that includes a coaxial excitation mirror positioned to direct excitation light directly to the bottom of a well of a multi-well plate. Fluorescence emission light that exits the well opening is collected by a relatively large coaxial emission mirror. The collected emission light is wavelength selected by the emission double monochromator. Selected emission light is detected by a photodetector module.
Abstract:
A two dimensional spatial radiation modulator rotated about a rotation axis to modulate components of an incident radiation beam to encode the beam. The modulator includes sub-regions in a first annular segment being patterned to form a pair of radiation filters having substantially complementary modulation functions. The pair of radiation filters produces a first encoded component with a characteristic determined by the relative intensities of radiation from the beam incident on the pair of filters. The modulator also includes sub-regions in a second annular segment being patterned to form a filter that produces a second encoded component with a characteristic determined by the total intensity of radiation from the beam incident on the filter.