Raytheon Company

Arete Associates

David N Sitter, Jr

Maurice J Halmos

Joseph C Marron

Gamze Erten

Justin S Grayer

Stephen C Lubard

J Kent Bowker

Anthony D Gleckler

John W McLean

Andrew James Griffis

Joseph J Ichkhan

Gregory J Fetzer

Asher Gelbart

Douglas Gugler

William L Ryder

David Miller

Shannon Bybee-Driscoll

A device includes an entrance pupil configured to receive light from a distant source. The device also includes an exit pupil configured to output the light to at least one component of an imaging system. The device further includes a plurality of lenses disposed optically between the entrance pupil and the exit pupil, where the lenses are grouped into an objective group and an eyepiece group. In addition, the device includes a housing surrounding the lenses and formed of a housing material. The lenses are formed of one or more lens materials selected based on a thermo-optical coefficient of the one or more lens materials and a coefficient of thermal expansion (CTE) of the housing material. The lens materials can be selected to have a thermo-optical coefficient that is closest to the CTE of the housing material among thermo-optical coefficients of a plurality of possible lens materials.

Athermal infrared optical telescope and method for manufacturing

A coherent imaging system produces coherent flood illumination directed toward a remote object and local oscillator (LO) illumination derived based on a same master oscillator as the flood illumination. A Doppler sensor receives the LO illumination and a return of flood illumination reflected off the object. Doppler shift data from the Doppler sensor, corresponding to a longitudinal velocity of the object relative to the imaging system, is used to produce Doppler-shifted LO illumination received by a low bandwidth, large format focal plane array (FPA), together with the return illumination from the object. Interference between the Doppler-shifted LO illumination and the return illumination facilitates producing an image of the object with the low bandwidth FPA despite the longitudinal velocity. Pixel intensities from the FPA are integrated over a period approaching the maximum interference frequency. The Doppler sensor and FPA may concurrently process return for a high energy laser target spot.

System for coherent imaging in dynamic engagements

A beam splitter configured to split incident light includes a polarization grating having a liquid crystal layer and a reflective sub-aperture beam splitter. The liquid crystal layer is configured to switch between an 'on' state and an 'off' state in response to an applied voltage. In the &#x201c;off&#x201d; state, the polarization grating angularly deviates and polarizes a portion of received incident light passing therethrough. In the &#x201c;on&#x201d; state, crystals of the polarization grating align with the incident light, allowing it to pass therethrough unimpeded and unpolarized. The beam splitter includes a plurality of sub-aperture mirrors which are spaced at randomly varying distances from one another, the mirrors being configured to reflect a portion of the incident light.

Beam splitter with switchable output beam

An on-axis four mirror anastigmat telescope includes an entrance pupil configured to receive light from an image, and a mirror assembly. The mirror assembly has a first reflective surface having a central aperture formed therein, a second reflective surface, a third reflective surface having a central aperture formed therein, a fourth reflective surface, and an aperture stop. The mirror assembly is configured to receive light from the image on a common axis and to reflect the light successively by the four coaxial reflective surfaces through the aperture stop. The telescope further comprises a detector configured to receive light from the mirror assembly. The central aperture formed in the first reflective surface defines a field stop to limit the field of view.

On-axis four mirror anastigmat telescope

An unobscured five-mirror afocal telescope includes an aperture configured to direct electromagnetic radiation to first, second, third, fourth and fifth mirrors, each configured to receive electromagnetic radiation and reflect electromagnetic radiation along a beam path. The five mirrors are arranged to sequentially reflect from one another electromagnetic radiation received via the aperture to produce a collimated output beam of the electromagnetic radiation at an exit pupil, with the five mirrors consisting of a three-element objective and a two-element eyepiece. A beam splitter may be disposed between the first mirror and the second mirror to direct short-wavelength electromagnetic radiation toward a device along a separate path.

Unobscured five-mirror afocal telescope

An apparatus includes at least one processor configured to determine a wavefront phase profile of return illumination reflected from a remote object, where the wavefront phase profile is based on interference between Doppler-shifted local oscillator (LO) illumination and the return illumination. The at least one processor is also configured to calculate a wavefront error based on a comparison between (i) the determined wavefront phase profile of the return illumination and (ii) a desired wavefront phase profile of a high energy laser (HEL) beam. The at least one processor is further configured to control a deformable mirror to at least partially compensate the HEL beam for the calculated wavefront error.

Laser beam projection system with dynamic phase compensation

Examples are directed to optimal field mappings that provide the highest contrast images for back-scanned imaging methods. The mappings can be implemented for back-scanned imaging with afocal optics including an anamorphic field correcting assembly configured to implement a non-rotationally symmetric field mapping between object space and image space to adjust distortion characteristics of the afocal optics to control image wander on a focal plane array. The anamorphic field correcting assembly can include one or more mirrors or lenses having non-rotationally symmetric aspherical departures.

Optical configurations for optical field mappings for back-scanned and line-scanned imagers

An apparatus includes a wavefront sensor configured to receive coherent flood illumination that is reflected from a remote object and to estimate wavefront errors associated with the coherent flood illumination. The apparatus also includes a beam director optically coupled to the wavefront sensor and having a telescope and an auto-alignment system. The auto-alignment system is configured to adjust at least one first optical device in order to alter a line-of-sight of the wavefront sensor. The wavefront errors estimated by the wavefront sensor include a wavefront error resulting from the adjustment of the at least one first optical device. The beam director could further include at least one second optical device configured to correct for the wavefront errors. The at least one second optical device could include at least one deformable mirror.

High-performance beam director for high-power laser systems or other systems

A laser beam projection system builds on a coherent imaging to project a tightly focused laser beam onto a remote object. Coherent flood illumination and local oscillator (LO) illumination are based on one master oscillator. The coherent flood illumination is directed toward a remote object, with a second laser beam directed onto an aimpoint on the same object. A Doppler sensor provides Doppler shift data used to produce Doppler-shifted LO illumination received by a focal plane array, together with the return flood illumination. Interference between the Doppler-shifted LO illumination and the return flood illumination facilitates imaging the object despite the velocity. The wavefront error of the flood illumined remote object image is computed and compared to the desired wavefront of the second laser beam at the aimpoint, with the difference applied to a deformable mirror to shape the second laser beam wavefront for obtaining a desired aimpoint intensity profile.

Optimal angular field mappings that provide the highest contrast images for back-scanned imaging are given. The mapping can be implemented for back-scanned imaging with afocal optics including an anamorphic field correcting assembly configured to implement a non-rotationally symmetric field mapping between object space and image space to adjust distortion characteristics of the afocal optics to control image wander on a focal plane array. The anamorphic field correcting assembly can include one or more mirrors having non-rotationally symmetric aspherical departures.

Reflective optical configurations with prescribed optical field mappings for back-scanned imagers

Examples are directed to optimal field mappings that provide the highest contrast images for time delay integration (TDI) imaging systems and methods. The mapping can be implemented for line-scanned imaging with optical systems including an anamorphic field correcting assembly configured to implement a non-rotationally symmetric field mapping between object space and image space to adjust distortion characteristics of the optics to control image wander on a focal plane array. The anamorphic field correcting assembly can include one or more mirrors or lenses having non-rotationally symmetric aspherical departures.

A method for cross-band apochromatic correction in a multi-element optical system. In one example, the method includes selecting a set of design wavelengths, determining a set of optical materials that are transmissive at each design wavelength, identifying a system of linear equations that describe the multi-element optical system in terms of a normalized optical power over the set of design wavelengths, generating multiple solutions for the system of linear equations, each solution defining a set of design optical materials selected from the set of optical materials and based at least in part on calculating mean squared difference values for wavelength pair combinations of design wavelengths in the set of design wavelengths, determining a merit value for each solution using a merit function, the merit value based on minimizing the mean squared difference values, ranking the merit values of the multiple solutions, and using at least one solution of the multiple solutions to design the multi-element optical system. In some examples, at least one design wavelength is a SWIR wavelength and at least one design wavelength is a LWIR wavelength.

Cross-band apochromatic correction and applications in the LWIR and SWIR bands

Optimal field mappings that provide the highest contrast images for back-scanned and time delay integration (TDI) imaging are given. The mapping can be implemented for back-scanned imaging with afocal optics including an anamorphic field correcting assembly configured to implement a non-rotationally symmetric field mapping between object space and image space to adjust distortion characteristics of the afocal optics to control image wander on a focal plane array. The anamorphic field correcting assembly can include one or more mirrors or lenses having non-rotationally symmetric aspherical departures. For optimal TDI imaging, anamorphic optics are also employed.

An afocal telescope configured for back-scanned imagery including a three mirror anastigmat and an optical element positioned proximate an intermediate image plane of the three mirror anastigmat and configured to adjust distortion characteristics of the afocal telescope to control image wander on a focal plane array. The optical element may be a field correcting lens or mirror, for example.

Growing community of inventors

Torrance, CA, United States of America

David N Sitter, Jr