Abstract:
A wide-field-of-view (WFOV) optical system includes a negative optical-power primary mirror configured to receive and reflect light from an image scene; a low optical-power secondary mirror configured to receive and reflect light from the primary mirror; a negative optical-power tertiary mirror configured to receive and reflect light from the secondary mirror; and a positive optical-power quaternary mirror configured to receive and reflect light from the tertiary mirror. The primary, secondary, tertiary and quaternary mirrors are configured to maintain an effective focal length (EFL) at edges of the field of view (FOV) of the optical system to be at least equal to a center of the FOV of the optical system so that a spatial resolution of the optical system essentially remains constant across the FOV.
Abstract:
An IR detector with a calibration source assembly (104) includes a cold cavity assembly tube (106) providing an internal vacuum (108), the tube (106) having a first end (110) providing a cold stop (112) and a second end (114) providing an IR focal plane (116) oriented towards the first end (110). The IR detector with a calibration source assembly (104) also includes a rotatable spectral filter wheel (118) optically coupled to an IR focal plane (116) of the detector, the filter wheel (118) having a plurality of areas (120) each of at least a minimum size, at least one area being a calibration area (120A). The calibration area includes: a substrate (122) having a first side (124) facing the IR focal plane (116) and a second side (126) opposite from the first side (124); a light transmitting edge section (128) disposed between the first side (124) and the second side (126); and, at least one light redirector (130) disposed at least partially within the substrate (122), the light redirector (130) structured and arranged to receive light from the edge (128) and to redirect the light out the first side (124). The IR detector with a calibration source assembly (104) also includes a light source (132) optically coupled to the edge section (128).
Abstract:
A two-channel spectrometer (20) has a shared objective (22) and a pair of slits (34, 40) at a common image plane (46). Each of the slits (34, 40) receives a portion of the output beam (22) of the shared objective (22) and is optimized for transmitting different wavelengths. A shared double-pass reflective triplet (48) receives the output beams of the slits. The output of the reflective triplet (48) is incident upon a beamsplitter (62), which sends a collimated first reflective triplet output (52) of a first wavelength to a first dispersive element (64), and a collimated second reflective triplet output (54) of a second wavelength to a second dispersive element (70). The outputs (66, 72) of the dispersive elements (64, 70) are directed back to the beamsplitter (62) and the reflective triplet (48) to imaging detectors (76, 78) located at two different locations of the common image plane (46).
Abstract:
A three-channel spectrometer including: a beamsplitter element that receives an incident radiation and transmits a first portion, a second portion, and a third portion of the incident radiation, a first slit that receives the first portion and transmits a first slit output radiation of a first wavelength range; a second slit that receives the second portion and transmits a second slit output radiation of a second wavelength range; a third slit that receives the third portion of the incident radiation and transmits a third slit output radiation of a third wavelength range; a common optical form that receives and collimates the first, second, and third slit output radiation; and a dispersive element that receives and reflects the collimated first, second, and third slit output radiation from the optical form.
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.