Abstract:
A millimeter-wave optical imaging system including an imaging detector located at a focal plane of the optical imaging system, the imaging detector being responsive to electromagnetic radiation in wavelength range of approximately 5-50 millimeters, an immersion lens directly coupled to the imaging detector and configured to focus the electromagnetic radiation onto the imaging detector, wherein the focal plane is located on a planar surface of the immersion lens and the imaging detector is directly coupled to the planar surface, a positive power primary mirror configured to reflect the electromagnetic radiation towards the immersion lens, and one of a Fresnel lens or a diffraction grating configured to receive and direct the electromagnetic radiation towards the primary mirror.
Abstract:
A system and method for measuring and removing jitter from an optical sensor includes a jitter stabilization system and at least one focal plane array. The jitter stabilization system is positioned at a shared focus of the focal plane array, which can be generated by an optical imager. A jitter signal of the jitter stabilization system makes a double pass through the system, contacting every reflective surface along the optical path within the system, before returning to a position sensing detector (PSD).
Abstract:
Methods and apparatus for sensor calibration of a system having an aperture, primary mirror, secondary mirror, and a sensor, such as an FPA IR sensor. A calibration system includes calibration energy sources with a movable first mirror configured to be selectively inserted into the optical path and select one of the calibration energy sources and a second mirror configured to image the selected calibration energy source.
Abstract:
An optical imaging system including refractive optics and a blocking component. The refractive optical having an entrance aperture and configured to receive optical radiation via an operational aperture, to focus the optical radiation onto a focal plane to form a telecentric image plane co-located with the focal plane, the operational aperture being co-located with the entrance aperture, having a diameter less than half a diameter of the entrance aperture, and being offset from a primary optical axis that bisects the entrance aperture by at least a radius of the entrance aperture, and a blocking component located at the entrance aperture on an opposite side of the primary optical axis from the operational aperture. The blocking component being configured to block the optical radiation from exiting the refractive optics via a region of the entrance aperture where the blocking component is located.
Abstract:
A dual-band refractive inverse telephoto lens system configured for mid-wave infrared (MWIR) and long-wave infrared (LWIR) operation. In certain examples the dual-band refractive inverse telephoto lens system includes first, second, third, and fourth lenses, each constructed from a material that is optically transparent in the mid-wave infrared and long-wave infrared spectral bands, and has an external pupil coincident with an aperture stop of the refractive inverse telephoto lens system, the aperture stop being located between the first, second, third, and fourth lenses and the infrared imaging detector to allow for 100% cold shielding.
Abstract:
An all-reflective coronagraph optical system for continuously imaging a wide field of view. The optical system can comprise a fore-optics assembly comprising a plurality of mirrors that reflect light rays, about a wide field of view centered around the Sun, to an aft-optics assembly that reflects the light rays to an image sensor. A fold mirror, having an aperture, is optically supported between the fore-optics assembly and the aft-optics assembly. The aperture defines an angular subtense (e.g., 1.0 degree) sized larger than the angular subtense of the Sun. The aperture facilitates passage of a direct solar image and a solar thermal load. A thermal control subsystem comprises a shroud radiatively coupled to each fore-optics mirror and the fold mirror. A cold radiator is thermally coupled to each shroud. Heaters adjacent fore optics mirrors and the fold mirror control temperature to provide a steady state optical system to minimize wavefront error.
Abstract:
A dual-band refractive optical system having an eyepiece-type arrangement and configured for mid-wave infrared and long-wave infrared operation. In one example the optical system includes a plurality of lenses, each constructed from a material that is optically transparent in the mid-wave infrared and long-wave infrared spectral bands. The lenses are arranged to receive infrared electromagnetic radiation in an operating waveband that includes at least a portion of the mid-wave infrared and at least a portion of the long-wave infrared spectral bands via a front external aperture stop and to focus the infrared electromagnetic radiation onto a rear image plane, the lenses being positioned between the front external aperture stop and rear image plane. The optical system can further include a corrector plate positioned coincident with the front aperture stop.
Abstract:
An optical sensor system having an extended elevation field of view and in which the optics are configured around an all-reflective four-mirror reimaging anastigmat used for afocal foreoptics and an all-reflective five-mirror reimaging anastigmat used for imaging optics. One example of an optical sensor system includes afocal foreoptics configured to receive and collimate electromagnetic radiation, the afocal foreoptics including an all-reflective, reimaging four-mirror anastigmat, an imaging detector, focal imaging optics positioned between the afocal foreoptics and the imaging detector and configured to receive the collimated beam of electromagnetic radiation from the afocal foreoptics and to focus the beam of electromagnetic radiation onto the imaging detector, the focal imaging optics including a reimaging five-mirror anastigmat, wherein a field of view of the system is determined at least in part by a combination of the afocal foreoptics and the focal imaging optics and covers at least 5 degrees in elevation.
Abstract:
Millimeter-wave optical imaging systems and methods. In one example, a mm-wave optical imaging system includes a mm-wave imaging detector located at a focal plane of the optical imaging system, an immersion lens directly coupled to the imaging detector and configured to focus the electromagnetic radiation onto the imaging detector, the immersion lens having a curved first surface and an opposing planar second surface, wherein the focal plane is located on the planar second surface and the imaging detector is directly coupled to the planar second surface, a positive power primary minor configured to reflect the electromagnetic radiation towards the immersion lens, and a Schmidt aspheric corrector configured to receive and direct the electromagnetic radiation towards the primary minor, wherein the system aperture stop is located on the Schmidt aspheric corrector.
Abstract:
A laser communications terminal configured for simultaneous two-way stabilized communications links to multiple ground sites. One example of such a laser communications terminal includes a plurality of laser channels, each including a channel transceiver configured to transmit and receive an optical signal, an afocal telescope optically coupled to each of the channel transceivers, a coelostat mirror pair optically coupled to the afocal telescope, and a plurality of beam steering mirrors, at least one beam steering mirror associated with each channel of the plurality of laser channels and configured to independently steer the corresponding optical signal within a field of view of the afocal telescope.