Multiband spatial heterodyne spectrometer and associated methods
First Claim
1. A multiband spatial heterodyne spectrometer for determining spectra of incident light in at least a first and a second wavelength band comprising:
- a beam splitter configured to split incident light and to direct the incident light upon a first and a second diffraction grating, wherein the first diffraction grating is configured for Littrow reflection of incident light of the first wavelength band at least one first order and Littrow reflection of incident light of the second wavelength band at least one second order, wherein the second diffraction grating is configured for Littrow reflection of light of the first wavelength band at the first order and of the second wavelength band at the second order, and wherein light reflected by the first and the second diffraction grating forms interference patterns;
an electronic camera for imaging the interference patterns, the camera comprising a detector having at least two rows of pixel sensors;
a dispersive device selected from the group consisting of a prism and a diffraction grating for separating the interference patterns into interference patterns corresponding to the first and second wavelength bands;
at least one anamorphic lens for imaging the interference patterns corresponding to the first and second wavelength bands a series of interferograms associated with different positions within the incident light on separate ones of the rows of pixel sensors; and
a processing device coupled to receive information from the detector and to compute spectra therefrom.
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Accused Products
Abstract
A multiband spatial heterodyne spectrometer for determining spectra in first and second wavelength bands has a beam splitter configured to split incident light and to direct the incident light upon a first and a second diffraction grating. The gratings are configured for Littrow reflection of incident light of the first wavelength band at a first order and Littrow reflection of incident light of the second wavelength band at a second order. Light reflected by the first and the second diffraction grating forms diffraction patterns that are imaged by an electronic camera. A dispersive device such as a prism or diffraction grating separates the imaged interference patterns onto separate rows of pixel sensors corresponding to the wavelength bands. A processing device receives information from the detector and computes spectra therefrom. In embodiments, the spectrometer is configured to compute hyperspectral images of a target.
35 Citations
18 Claims
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1. A multiband spatial heterodyne spectrometer for determining spectra of incident light in at least a first and a second wavelength band comprising:
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a beam splitter configured to split incident light and to direct the incident light upon a first and a second diffraction grating, wherein the first diffraction grating is configured for Littrow reflection of incident light of the first wavelength band at least one first order and Littrow reflection of incident light of the second wavelength band at least one second order, wherein the second diffraction grating is configured for Littrow reflection of light of the first wavelength band at the first order and of the second wavelength band at the second order, and wherein light reflected by the first and the second diffraction grating forms interference patterns; an electronic camera for imaging the interference patterns, the camera comprising a detector having at least two rows of pixel sensors; a dispersive device selected from the group consisting of a prism and a diffraction grating for separating the interference patterns into interference patterns corresponding to the first and second wavelength bands; at least one anamorphic lens for imaging the interference patterns corresponding to the first and second wavelength bands a series of interferograms associated with different positions within the incident light on separate ones of the rows of pixel sensors; and a processing device coupled to receive information from the detector and to compute spectra therefrom. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A multiband spatial heterodyne imaging device comprising:
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a beam splitter configured to split light received from an aperture and to direct the light upon a first and a second diffraction grating, wherein each of the first and second diffraction grating is configured for Littrow reflection of incident light of a first wavelength band at a first order, the first order not being one, and Littrow reflection of incident light of a second wavelength band at a second order, and wherein light reflected by the first and the second diffraction grating forms interference patterns; an electronic camera for imaging the interference patterns, the camera comprising a detector having rows of pixel sensors; a dispersive device selected from the group consisting of a prism and a diffraction grating for separating the interference patterns into interference patterns corresponding to the first and second wavelength bands; at least one anamorphic lens for imaging the interference patterns corresponding to the first and second wavelength bands a series of interferograms associated with different positions within the incident light on separate ones of the rows of pixel sensors; wherein data from the plurality of rows of pixel sensors encodes positional information within the stripe of the field of view; and a processing device coupled to receive information from the detector and to compute images therefrom. - View Dependent Claims (12, 13, 14, 15)
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16. A multiband spatial heterodyne spectrometer for determining spectra of incident light in at least a first and a second wavelength band comprising:
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a beam splitter configured to split incident light and to direct the incident light upon a first and a second diffraction grating, wherein each of the first and second diffraction grating is configured for Littrow reflection of incident light of the first wavelength band at a first order and Littrow reflection of incident light of the second wavelength band at a second order, and wherein light reflected by the first and the second diffraction grating forms interference patterns; an electronic camera for imaging the interference patterns, the camera comprising a first and a second detector each having at least one row of pixel sensors; at least one dichroic filter for separating the interference patterns into interference patterns corresponding to the first and second wavelength bands, wherein the interference pattern corresponding to the first wavelength band is focused upon the first detector, and the interference pattern corresponding to the second wavelength band is focused upon the second detector; and a processing device coupled to receive information from the first and second detectors and to compute spectra therefrom. - View Dependent Claims (17)
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18. A multiband spatial heterodyne spectrometer for determining spectra of incident light in at least a first and a second wavelength band comprising:
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a beam splitter configured to split incident light and to direct the incident light upon a first and a second diffraction grating, wherein the first diffraction grating is configured for Littrow reflection of incident light of the first wavelength band at a first order and Littrow reflection of incident light of the second wavelength band at a second order, wherein the second diffraction grating is configured for Littrow reflection of light of the first band at a third order, and wherein light reflected by the first and the second diffraction grating forms interference patterns; an electronic camera for imaging the interference patterns, the camera comprising a detector having at least two rows of pixel sensors; a dispersive device selected from the group consisting of a prism and a diffraction grating for separating the interference patterns into interference patterns corresponding to the first and second wavelength bands on separate rows of pixel sensors; and a processing device coupled to receive information from the detector and to compute spectra therefrom.
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Specification