Abstract: Various embodiments provide a flat field Schmidt-type telescope including a spherical primary mirror, an aspheric correcting plate spaced apart from the primary mirror, a detector disposed between the primary mirror and the corrector plate, and a field lens disposed between the primary mirror and the detector. The field lens is configured to reshape a curved field plane formed by the primary mirror into a flat field plane. A material of the field lens is selected to transmit in the infrared wavelength range (e.g., SWIR and/or MWIR) and is selected to have a desired refractive index so as to achieve a field of view (FOV) of the telescope greater than approximately 10 degrees.

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: In one or more embodiments, a multi-axis articulated solar light shade that protects elements of a space-based sensor from direct solar illumination includes a base; a partial conical baffle tube having a first end portion, a second end portion, an elongated curved portion defining a shade between the first and second end portions, and an opening defined in an interior of the elongated curved portion, the first end portion rotatably attached to the base; and a visor pivotably attached to the second end portion. The partial conical baffle tube may be selectively rotated about a sensor line-of-sight in response to the sun's position relative to the sensor line-of-sight; and the visor may be selectively pivoted relative to the partial conical baffle tube in response to the sun's position relative to the sensor line-of-sight so as to protect the sensor from the direct solar illumination at any given time or any given orbital position.

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 steerable-light-path optical device includes a light transceiver having an external light path associated therewith, and a path-steering device that controls the direction of the light path relative to a steering axis. The path-steering device has a first beam-deviation optical element including a first prism structure having a first diffraction grating thereon, and a second beam-deviation optical element including a second prism structure having a second diffraction grating thereon. The steering axis passes through the first and second beam-deviation optical elements. A rotational drive is operable to rotate at least one of the first beam-deviation optical element and the second beam-deviation optical element, and preferably both of the beam-deviation optical elements, about the steering axis.

Abstract: An apparatus and method for effecting and changing optical distortions is disclosed. The apparatus includes a beam imaging apparatus including a first deformable mirror, a second deformable mirror, and a beam-steering apparatus. The beam-steering apparatus includes a plurality of planar tiltable mirrors arranged to define a radiation beam path therebetween, wherein the plurality of planar tiltable mirrors comprises at least three tiltable mirrors. A mirror drive system is configured to tilt each respective planar mirror about its respective axis of rotation or axes of rotation and a controller is configured to control deformation of a reflective surface of the first and the second deformable mirrors.

Abstract: In one or more embodiments, an all-reflective optical system includes a primary mirror of ellipsoidal configuration, a secondary mirror of hyperboloidal configuration facing the primary mirror, and an eye-piece that includes: a positive-powered tertiary mirror having a majority of positive power that is expected in the eye-piece and configured to substantially collimate light rays incident thereon; and a negative-powered near-flat quaternary mirror having lesser power than the tertiary mirror and configured to receive the substantially collimated light rays from the tertiary mirror, further collimate the received light rays and reflect the further collimated light rays to an exit pupil. The primary mirror, the secondary mirror and the eye-piece thereby form an afocal optical system.

Abstract: Various embodiments provide an apparatus and method for shaping a laser beam profile in which the apparatus includes a reformatting optical system configured to reformat a laser beam having a Gaussian intensity profile into a radiation beam having a top hat intensity profile; and a Fourier transforming optical system configured to transform the radiation beam having the top hat intensity profile into a radiation beam having a Bessel or sinc function intensity profile.

Abstract: Provided is an infrared imaging optical system with an advantageously varying focal length across the field of view. More specifically, in a particular embodiment, provided is an inverse telephoto lens group having a field of view on the order of at least two radians. The focal length of the lens group is structured and arranged to vary in a pre-determined fashion across the field of view. An IR detector is optically coupled to the inverse telephoto lens group. A pupil is disposed between the IR detector and the inverse telephoto lens group.

Abstract: An imaging optical system includes a set of mirrors including at least three mirrors on a beam path. Only a last mirror on the beam path has a positive optical power and all other mirrors have negative optical power. The sum of the optical powers of the mirrors is zero. An external posterior aperture stop is on the beam path between the last mirror and the image plane. A back focal length of the optical system is equal to or greater than an effective focal length of the optical system. The field of view is large, and typically at least 30-40 degrees in one plane.

Abstract: A beam-steering apparatus comprises a set of planar tiltable mirrors positioned to define a light beam path therebetween. The set of planar tiltable mirrors comprises from three to five planar tiltable mirrors. Each of the planar tiltable mirrors has a center of rotation lying in a plane of the mirror and each of the planar tiltable mirrors is tiltable about one axis of rotation or two orthogonal axes of rotation that lie in the plane of the mirror. The total number of axes of rotation about which the planar tiltable mirrors of the set of planar tiltable mirrors can tilt is at least five. A mirror drive system tilts each respective planar mirror about its respective axis of rotation or axes of rotation. With this apparatus, an input or output light beam path is steerable over two angular, one rotational, and two lateral-position degrees of freedom.

Abstract: A coude gimbal structure includes a two-axis gimbal system having an outer gimbal pivotable about a first rotational axis, and an inner gimbal supported on the outer gimbal and pivotable about a second rotational axis which intersects the first rotational axis at an intersection point. A folded afocal three-mirror anastigmat has a positive-optical-power primary mirror, a negative-optical-power secondary mirror, and a positive-optical-power tertiary mirror, and a first flat fold mirror, and a second flat fold mirror. A beam path incident upon the primary mirror is reflected from the primary mirror to the secondary mirror. The tertiary mirror lies on the second rotational axis, the first flat fold mirror redirects the beam path reflected from the secondary mirror to the tertiary mirror, and the second flat fold mirror lies at the intersection point and redirects the beam path reflected from the tertiary mirror along the first rotational axis.

Abstract: Provided is a calibration source IR assembly for an IR detector including an IR focal plane. The calibration assembly includes a rotatable spectral filter wheel optically coupled to an IR focal plane of the detector, the filter wheel having a plurality of areas each of at least a minimum size. At least one area being a calibration area, the calibration area including: a substrate having a first side facing the IR focal plane and a second side opposite from the first side; a light transmitting edge section disposed between the first side and the second side; and at least one light redirector disposed at least partially within the substrate, the light redirector structured and arranged to receive light from the edge and to redirect the light out the first side. A light source optically coupled to the edge section. An IR detector including the improvement of such a calibration source IR assembly is also provided.

Abstract: An optical pulse-width modifier structure includes a first diffraction grating and an optically unpowered reversing mirror. An optical path extends between the first diffraction grating and the optically unpowered reversing mirror. A second diffraction grating lies on the optical path between the first diffraction grating and the optically unpowered mirror. A set of optically powered mirrors lies on the optical path between the first diffraction grating and the second diffraction grating. The diffraction gratings and mirrors are positioned such that an input light beam is diffracted from the first diffraction grating, reflected from each of the set of optically powered mirrors, diffracted from the second diffraction grating, reflected from the optically unpowered reversing mirror back to the second diffraction grating, diffracted from the second diffraction grating, reflected from each of the set of optically powered mirrors, and diffracted from the first diffraction grating as an output light beam.

Abstract: Provided is an infrared imaging optical system with an advantageously varying focal length across the field of view. More specifically, in a particular embodiment, provided is an inverse telephoto lens group having a field of view on the order of at least two radians. The focal length of the lens group is structured and arranged to vary in a pre-determined fashion across the field of view. An IR detector is optically coupled to the inverse telephoto lens group. A pupil is disposed between the IR detector and the inverse telephoto lens group.

Abstract: A coude gimbal structure includes a two-axis gimbal system having an outer gimbal pivotable about a first rotational axis, and an inner gimbal supported on the outer gimbal and pivotable about a second rotational axis which intersects the first rotational axis at an intersection point. A folded afocal three-mirror anastigmat has a positive-optical-power primary mirror, a negative-optical-power secondary mirror, and a positive-optical-power tertiary mirror, and a first flat fold mirror, and a second flat fold mirror. A beam path incident upon the primary mirror is reflected from the primary mirror to the secondary mirror. The tertiary mirror lies on the second rotational axis, the first flat fold mirror redirects the beam path reflected from the secondary mirror to the tertiary mirror, and the second flat fold mirror lies at the intersection point and redirects the beam path reflected from the tertiary mirror along the first rotational axis.

Abstract: A beam-steering apparatus comprises a set of planar tiltable mirrors positioned to define a light beam path therebetween. The set of planar tiltable mirrors comprises from three to five planar tiltable mirrors. Each of the planar tiltable mirrors has a center of rotation lying in a plane of the mirror and each of the planar tiltable mirrors is tiltable about one axis of rotation or two orthogonal axes of rotation that lie in the plane of the mirror. The total number of axes of rotation about which the planar tiltable mirrors of the set of planar tiltable mirrors can tilt is at least five. A mirror drive system tilts each respective planar mirror about its respective axis of rotation or axes of rotation. With this apparatus, an input or output light beam path is steerable over two angular, one rotational, and two lateral-position degrees of freedom.

Abstract: Provided is a calibration source IR assembly for an IR detector including an IR focal plane. The calibration assembly includes a rotatable spectral filter wheel optically coupled to an IR focal plane of the detector, the filter wheel having a plurality of areas each of at least a minimum size. At least one area being a calibration area, the calibration area including: a substrate having a first side facing the IR focal plane and a second side opposite from the first side; a light transmitting edge section disposed between the first side and the second side; and at least one light redirector disposed at least partially within the substrate, the light redirector structured and arranged to receive light from the edge and to redirect the light out the first side. A light source optically coupled to the edge section. An IR detector including the improvement of such a calibration source IR assembly is also provided.

Abstract: An imaging optical system includes a set of mirrors including at least three mirrors on a beam path. Only a last mirror on the beam path has a positive optical power and all other mirrors have negative optical power. The sum of the optical powers of the mirrors is zero. An external posterior aperture stop is on the beam path between the last mirror and the image plane. A back focal length of the optical system is equal to or greater than an effective focal length of the optical system. The field of view is large, and typically at least 30-40 degrees in one plane.

Abstract: An optical pulse-width modifier structure includes a first diffraction grating and an optically unpowered reversing mirror. An optical path extends between the first diffraction grating and the optically unpowered reversing mirror. A second diffraction grating lies on the optical path between the first diffraction grating and the optically unpowered mirror. A set of optically powered mirrors lies on the optical path between the first diffraction grating and the second diffraction grating. The diffraction gratings and mirrors are positioned such that an input light beam is diffracted from the first diffraction grating, reflected from each of the set of optically powered mirrors, diffracted from the second diffraction grating, reflected from the optically unpowered reversing mirror back to the second diffraction grating, diffracted from the second diffraction grating, reflected from each of the set of optically powered mirrors, and diffracted from the first diffraction grating as an output light beam.