A reconstruction matrix used for calculating a hyperspectral data-cube includes rows of periodic functions. Each row of the reconstruction matrix corresponds to a selected wavelength and each column corresponds to a selected retardance of an interferometer. The periodic functions have as a parameter the selected wavelength of the corresponding row and are sampled at the selected retardances of each of the corresponding columns. An interferogram data-cube is obtained and includes an array of one or more simultaneously measured interferograms. Each row of the interferogram data-cube corresponds to one of the selected retardances and each column corresponds to a different interferogram from the simultaneously measured interferograms. A set of matrix-vector products for each of the interferograms is formed by multiplying the reconstruction matrix with a column of the interferogram data-cube to form the hyperspectral data-cube.

A system and process scans a target area at a distance of 3-30 m for one or more materials. Scanning is performed by a coherent transmit beam aimed with the help of a thermal camera. The active source of the beam is a supercontinuum (SC) laser. The transmitted source beam is modulated by a high-speed Fourier-transform spectrometer prior to interaction with the target. Target reflected source beam is detected by an infrared detector, along with a reference portion of the transmitted source beam, as a series of interferograms; passed through a digitizer for digitizing the interferograms; and processed to producing spectrograms, wherein the spectrograms are indicative of one or more materials on the target.

A technique and device to determine the spectrum of electromagnetic radiation in a certain range of wavelengths comprising: splitting said radiation into more than one beam; let these beams counter-propagate in a Sagnac-type ring interferometer; and imprinting a wavelength-dependent angular tilt onto the wavefront of each beam by at least one dispersive element which preferably is a transmission grating or grism; and re-combining the multiple beams on a detector that exhibits spatial resolution and can therefore resolve the fringes formed by interference; and perform the mathematical operations to determine the spectrum of said radiation from the obtained interferogram, wherein the dispersive element is mounted on a stage providing linear and/or rotational movement.

Disclosed is a linear array scanning Brillouin scattering elastic imaging device. In the device, a signal generating system consists of a narrow linewidth continuous wave laser, a half-wave plate, a beam expander, a Y-direction scanning galvanometer, a microlens array, a pinhole array filter, a first plano-convex lens, a polarization beam splitter, a quarter-wave plate and a microscope objective. A signal receiving system consists of a microscope objective, a quarter-wave plate, a polarization beam splitter and an eight-channel optical collimator array. Each channel of an eight-channel spectrometer consists of an optical collimator, a convex lens, a scanning Fabry-Perot interferometer, a photomultiplier tube and an eight-channel photon collection card.

A system and process scans a target area at a distance of 3-30 m for one or more materials. Scanning is performed by a coherent transmit beam aimed with the help of a thermal camera. The active source of the beam is a supercontinuum (SC) laser. The transmitted source beam is modulated by a high-speed Fourier-transform spectrometer prior to interaction with the target. Target reflected source beam is detected by an infrared detector, along with a reference portion of the transmitted source beam, as a series of interferograms; passed through a digitizer for digitizing the interferograms; and processed to producing spectrograms, wherein the spectrograms are indicative of one or more materials on the target.

A voltage is applied to a liquid-crystal variable retarder that monotonically changes a retardance and changes a first derivative with respect to time of the retardance of the liquid-crystal variable retarder over a time period. An interferogram of light passing through the liquid-crystal variable retarder is measured during the time period.

A voltage is applied to a liquid-crystal variable retarder that monotonically changes a retardance and changes a first derivative with respect to time of the retardance of the liquid-crystal variable retarder over a time period. An interferogram of light passing through the liquid-crystal variable retarder is measured during the time period.

A reconstruction matrix used for calculating a hyperspectral data-cube includes rows of periodic functions. Each row of the reconstruction matrix corresponds to a selected wavelength and each column corresponds to a selected retardance of an interferometer. The periodic functions have as a parameter the selected wavelength of the corresponding row and are sampled at the selected retardances of each of the corresponding columns. An interferogram data-cube is obtained and includes an array of one or more simultaneously measured interferograms. Each row of the interferogram data-cube corresponds to one of the selected retardances and each column corresponds to a different interferogram from the simultaneously measured interferograms. A set of matrix-vector products for each of the interferograms is formed by multiplying the reconstruction matrix with a column of the interferogram data-cube to form the hyperspectral data-cube.

An apparatus includes a liquid-crystal polarization interferometer that causes an optical path delay between a first and a second polarization of input light. The liquid-crystal polarization interferometer includes a liquid-crystal variable retarder that provides a variable retardance in response to a voltage applied across the liquid-crystal cell. First and second polarizers are located on opposing sides of the liquid-crystal cell. The apparatus includes an image sensor that senses interferograms based on output light that passes through the liquid-crystal polarization interferometer. The apparatus includes a color filter that filters one of the input light and the output light. The color filter has a spectral transmission characteristic that passes more light in a blue spectral region that in a red spectral region.

An incoming laser source beam is projected to a glass disc having a frosted upper surface. A refracted beam and a reflected beam are produced from the laser source beam. The refracted beam is reflected back to and through the glass disc to combine with the reflected beam to form an interference pattern on the target.