Abstract: One embodiment disclosed is a spectrometry system for collecting spatially and temporally co-registered hyperspectral data covering multiple spectral bands. The spectrometry system includes a single entrance slit for receiving light and a plurality of disperser elements operating over a plurality of distinct spectral bands to disperse the received light into constituent spectral channels. The system also includes a plurality of collimating and imaging optic elements that receive and re-image the dispersed light. The system also includes at least two focal plane arrays affixed in a common plane and configured to receive the re-imaged dispersed light, each of the at least two focal plane arrays being dedicated to sensing a distinct spectral band of the dispersed light.

Abstract: A multi-channel imaging spectrometer and method of use thereof. One example of the multi-channel imaging spectrometer includes a single entrance slit, a double pass reflective triplet and at least a pair of diffraction gratings. The spectrometer is configured to receive and collimate an input beam from the entrance slit, to split the collimated beam into two spectral sub-bands using a beamsplitter, and to direct each sub-band to one of the pair of diffraction gratings. The diffraction gratings are each configured to disperse the received portion of the collimated beam into its constituent colors, and redirect the dispersed outputs through the reflective triplet to be imaged into an image sensor located at a focal plane aligned with the entrance slit.

Abstract: A reflective optical form that has both a telecentric image and a real entrance pupil. In one example, a non-relayed optical imaging system includes a real entrance pupil configured to admit a beam of electromagnetic radiation, an image plane, and a reflective triplet including a negative primary mirror, a positive secondary mirror optically coupled to the primary mirror, a negative tertiary mirror optically coupled to the secondary mirror, the reflective triplet configured to receive the beam of electromagnetic radiation from the real entrance pupil and to focus the beam of electromagnetic radiation onto the image plane to form a telecentric image at the image plane.

Abstract: An imaging platform minimizes image distortion when there is relative motion of the imaging platform with respect to the scene being imaged where the imaging platform may be particularly susceptible to distortion when it is configured with a wide field of view or high angular rate of movement, or when performing long-stares at a given scene (e.g., for nighttime and low-light imaging.) Distortion correction may be performed by predicting distortion due to the relative motion of the imaging platform, determining optical transformations to prevent the distortion, dynamically adjusting the optics of the imaging platform during exposure, and performing digital image correction.

Abstract: A radiation shielded optical system. In one example, a radiation shielded optical system includes a labyrinthine housing having an entrance and defining a cavity, a detector positioned within the cavity of the housing, the housing configured to provide substantially 4-pi steradian radiation shielding for the detector. The optical system further includes a rear-stopped optical sub-system having a rear aperture stop positioned proximate the entrance of the housing and configured to direct an optical beam through the rear aperture stop and the entrance into the housing, and a fold mirror positioned within the housing and configured to reflect the optical beam onto the detector.

Abstract: A jitter sensing mechanism for a gimbaled optical sensor system. In one example, the jitter sensing mechanism includes a faceted retro-mirror configured to allow a double-pass line-of-sight monitoring beam to sense line-of-sight jitter in a multi-axis gimbaled optical sensor system where the inner-most gimbal axis includes a 2:1 gain mirror.

Abstract: A dispersive infrared spectrometer in which only a minimum number of optical components, for example, the detector sub-system only, are housed within a cold/cryogenic dewar and the remaining optical components are at ambient temperature during operation of the spectrometer. In one example, the spectrometer includes a slit substrate with a highly reflective surface, and the optical components of the spectrometer are configured and arranged such that for all in-band wavelengths, substantially all off-slit optical paths in the detector field of view are retro-reflected off the reflective surface of the slit substrate into the cryogenic dewar.

Abstract: A wide field-of-view infrared optical imaging system with extended spectral coverage into the 1.0 to 2.5 ?m wavelength range. In one example, an optical imaging system includes an imaging detector sensitive to light in a wavelength range of at least 1.0 ?m to 5.0 ?m, and a plurality of lenses optically coupled together and configured to focus incoming light onto the imaging detector, the plurality of lenses each comprised of a material that is transparent to the light in the wavelength range of at least 1.0 ?m to 5.0 ?m, wherein a pupil of the optical imaging system is located external to the plurality of lenses between the plurality of lenses and the imaging detector.

Abstract: Various embodiments provide a Cassegrain-like telescope. The Cassegrain-like telescope includes a primary mirror; a secondary mirror spaced apart from the primary mirror, the primary mirror and the second mirror configured to form a focal surface; and an optical aberrations corrector having a plurality of lenses, the optical aberrations corrector being disposed between the secondary mirror and the focal surface, the optical aberration corrector being configured to correct optical aberrations of the primary mirror and the secondary mirror. A material of the plurality of lenses is selected to transmit radiation in a wavelength range between approximately 0.4 ?m and approximately 12 ?m, and is selected to have variations in refractive index below about 0.05 so as to reduce chromatic aberration to a level such that an average root mean square of wave front error (RMS WFE) is less than approximately 0.08.

Abstract: An imaging platform minimizes image distortion when there is relative motion of the imaging platform with respect to the scene being imaged where the imaging platform may be particularly susceptible to distortion when it is configured with a wide field of view or high angular rate of movement, or when performing long-stares at a given scene (e.g., for nighttime and low-light imaging.) Distortion correction may be performed by predicting distortion due to the relative motion of the imaging platform, determining optical transformations to prevent the distortion, dynamically adjusting the optics of the imaging platform during exposure, and performing digital image correction.

Abstract: A dispersive infrared spectrometer in which only a minimum number of optical components, for example, the detector sub-system only, are housed within a cold/cryogenic dewar and the remaining optical components are at ambient temperature during operation of the spectrometer. In one example, the spectrometer includes a slit substrate with a highly reflective surface, and the optical components of the spectrometer are configured and arranged such that for all in-band wavelengths, substantially all off-slit optical paths in the detector field of view are retro-reflected off the reflective surface of the slit substrate into the cryogenic dewar.

Abstract: An all-reflective afocal optical system including an aspheric beam steering mirror positioned at an exit pupil of the afocal optical system. In one example, an all-reflective afocal optical imaging system includes a sensor, a afocal optical apparatus including a plurality of minors optically coupled together and configured to receive light rays through an entrance pupil of the afocal optical imaging system and to substantially collimate the light rays to provide a collimated optical beam to an exit pupil, and an aspheric beam steering mirror positioned at the exit pupil and configured to receive the collimated optical beam and to direct the collimated optical beam to the sensor.

Abstract: An imaging assembly for a spectrometer includes a substrate with first and second modules thereon containing respective arrays of detector elements positioned so the arrays are elongated along a first axis with a gap therebetween. A third module including a third array of detector elements is also thereon, spaced from the first axis, at least as long as the gap, and smaller than the elongation of either of the first or second arrays. Further thereon are first and second slits elongated along a second axis spaced from and generally parallel to the first axis, each being at least as long as the respective arrays. A third slit at least as long as the gap is also therein, spaced from the first axis, second axis, and third array such that the gap, third slit, and third array are generally along a third axis generally perpendicular to the first and second axis.

Abstract: A jitter sensing mechanism for a gimbaled optical sensor system. In one example, the jitter sensing mechanism includes a faceted retro-minor configured to allow a double-pass line-of-sight monitoring beam to sense line-of-sight jitter in a multi-axis gimbaled optical sensor system where the inner-most gimbal axis includes a 2:1 gain mirror.

Abstract: An optical system includes a primary mirror of a positive-powered concave substantially paraboloidal configuration configured to reflect light incident thereupon; a secondary mirror of a negative-powered convex hyperboloidal configuration facing the primary mirror configured to receive the light reflected from the primary mirror and redirect the light reflected from the primary mirror; a positive-powered tertiary mirror configured to substantially reimage and reflect divergent light rays incident from the secondary mirror; and a powered quaternary mirror configured to receive the reimaged light rays from the tertiary mirror, and to relay the received reimaged light rays to a focal point.

Abstract: A spectrometer comprises a detector array and a prism. The prism comprises a first prism element comprising a substantially crystalline crown material, and a second prism element contacting the first prism element, the second prism element comprising a substantially crystalline flint material. The spectrometer further includes optics configured to direct light at least twice through the prism. The prism is configured to disperse light received from the optics at an incident angle therethrough into constituent spectra in visible and infrared wavelength bands that are dispersed from the prism at angles offset from the incident angle. The constituent spectra are directed onto the detector array with approximately equal dispersion across the visible and infrared wavelength bands. Among other things, desirable material selections for the first and second prism elements are also disclosed.

Abstract: Various embodiments provide an optical system including an optical spectrometer, a first negative power mirror configured and arranged to receive radiation from a far-field object, a second positive power mirror configured and arranged to receive radiation reflected by the first negative power mirror, and a third positive power mirror configured and arranged to receive radiation reflected by the second positive mirror and to direct the radiation towards an entrance slit of the optical spectrometer.

Abstract: A spectrometer comprises a detector array and a prism. The prism comprises a first prism element comprising a substantially crystalline crown material, and a second prism element contacting the first prism element, the second prism element comprising a substantially crystalline flint material. The spectrometer further includes optics configured to direct light at least twice through the prism. The prism is configured to disperse light received from the optics at an incident angle therethrough into constituent spectra in visible and infrared wavelength bands that are dispersed from the prism at angles offset from the incident angle. The constituent spectra are directed onto the detector array with approximately equal dispersion across the visible and infrared wavelength bands. Among other things, desirable material selections for the first and second prism elements are also disclosed.

Abstract: An infrared imaging optical system for focusing infrared radiation on an infrared detector, including: a front lens group having a negative optical power to receive infrared radiation and including a first front lens and a second front lens each with at least one aspherical surface; an intermediate lens group that receives the infrared radiation from the front lens group and includes a first intermediate lens, a second intermediate lens, and a third intermediate lens each with at least one aspherical surface; and a rear lens group having positive optical power, wherein the rear lens group receives the infrared radiation from the intermediate lens group and includes a first rear lens and a second rear lens each with at least one aspherical surface, and a third rear lens, wherein the imaging optical system has a stop between the rear lens group and a focal plane at said infrared detector.

Abstract: An imaging assembly for a spectrometer includes a substrate with first and second modules thereon containing respective arrays of detector elements positioned so the arrays are elongated along a first axis with a gap therebetween. A third module including a third array of detector elements is also thereon, spaced from the first axis, at least as long as the gap, and smaller than the elongation of either of the first or second arrays. Further thereon are first and second slits elongated along a second axis spaced from and generally parallel to the first axis, each being at least as long as the respective arrays. A third slit at least as long as the gap is also therein, spaced from the first axis, second axis, and third array such that the gap, third slit, and third array are generally along a third axis generally perpendicular to the first and second axis.