Beam Engineering for Advanced Measurements Co.

US Government As Represented by the Secretary of the Army

Northrop Grumman Systems Corporation

Defense Advanced Research Projects Agency (darpa)

David E Roberts

Nelson V Tabirian

Diane Steeves

Brian Kimball

Anna Tabirian

Svetlana Serak

Olena Uskova

Zhi J Liao

Sarik R Nersisyan

Douglas P Stanley

Justin L Sigley

Carl S King

Arthur B Thompson

Paul Calhoun

Robert Winsor

Diffractive optical structures, lenses, waveplates, devices, systems, and methods, which have the same effect on light regardless of the polarization state of the light, utilizing systems of polarization discriminator diffractive waveplate optics and differential polarization converters with special arrangements that do not require introducing spatial separation between the layers.

Polarization-independent diffractive optical structures

Opto-mechanical assemblies, systems, devices and methods for pointing laser and other optical beams, and for directing the field of view of sensors are disclosed. The assemblies consist of thin rotating optical elements of a type that diffracts the optical beam over a wide field of regard in two dimensions, and the angle of incidence of the optical beam or line of sight impinging on the optical elements are dynamically controlled maximizing the diffraction efficiency of the optical elements.

Diffractive beam steering system with high efficiency

Methods, systems and devices for diffractive waveplate lens and mirror systems allowing electronically pointing and focusing light at different focal planes. The system can be incorporated into a variety of optical schemes for providing electrical control of transmission. In another embodiment, the system comprises diffractive waveplates of different functionality to provide a system for controlling not only focusing but other propagation properties of light including direction, phase profile, and intensity distribution. The diffractive waveplate lens and mirror systems are applicable to optical communication systems.

Diffractive waveplate lenses and applications

Optical beam steering and focusing systems, devices, and methods that utilize diffractive waveplates are improved to produce high efficiency at large beam deflection angles, particularly around normal incidence, by diffractive waveplate architectures comprising a special combination of liquid crystal polymer diffractive waveplate both layers with internal twisted structure and at a layer with uniform structure.

High-efficiency wide-angle beam steering system

Diffractive optical structures, lenses, waveplates, devices, systems and methods, which have the same effect on light regardless of temperature within an operating temperature range. Temperature-compensated switchable diffractive waveplate systems, in which the diffraction efficiency can be maximized for the operating wavelength and temperature by means of adjustment of the electric potential across the liquid crystal or other anisotropic material in the diffracting state of the diffractive state, based on prior measurements of diffraction efficiency as a function of wavelength and temperature. The switchable diffractive waveplates can be a switchable diffractive waveplate diffuser, a switchable cycloidal diffractive waveplate, and a switchable diffractive waveplate lens. An electronic controller can apply an electric potential to the switchable diffractive waveplate. Amplitudes of the electric potential can be determined from lookup tables such that diffraction efficiency at an operating wavelength and measured temperature is maximized. A communications channel can transfer the measured temperature from temperature measurement means to the electronic controller.

Diffractive waveplate devices that operate over a wide temperature range

Diffractive optical structures, lens, waveplates, systems and methods of combinations of CDWs (cycloidal diffractive waveplates) and PVGs (polarization volume gratings) that result in high efficiency polarization-insensitive diffraction. Although our modelling and experiments were performed for structures with optical axis orientation periodic along one of the Cartesian coordinates parallel to the plane of the structure, the results are applicable to more complex structures such as diffractive waveplate lenses. The focusing performance of such structures can be predicted by considering the structure to be locally periodic along one axis.

Methods of fabricating optical lenses and mirrors, systems and composite structures based on diffractive waveplates, and fields of application of said lenses and mirrors that include imaging systems, astronomy, displays, polarizers, optical communication and other areas of laser and photonics technology. Diffractive lenses and mirrors of shorter focal length and larger size, with more closely spaced grating lines, and with more exacting tolerances on the optical characteristics, can be fabricated than could be fabricated by previous methods.

Methods of diffractive lens and mirror fabrication

Modulated circular polarization viewing systems and methods that cause temporal modulation of color, brightness, or both, of objects treated with materials having differential polarization reflectance.

Modulated circular polarization viewing system

Methods, systems and devices for diffractive waveplate lens and mirror systems allowing electronically focusing light at different focal planes. The system can be incorporated into a variety of optical schemes for providing electrical control of transmission. In another embodiment, the system comprises diffractive waveplates of different functionality to provide a system for controlling not only focusing but other propagation properties of light including direction, phase profile, and intensity distribution.

Diffractive waveplate lenses, mirrors, devices, systems and methods for performing imaging over a broad spectral band in imaging systems, such as but not limited to astronomical imaging, surveillance imaging, and in communication systems, such as laser communication systems. Corrector mirrors are used with a flat diffractive wave diffractive waveplate lens so that chromatic aberrations of the diffractive waveplate lens are reduced with the imaging system.

Broadband imaging with diffractive waveplate coated mirrors and diffractive waveplate objective lens

Optical beam shaping systems and methods can include an illumination source and a diffractive waveplate diffuser. The diffractive waveplate diffuser includes a layer of patterned optically anisotropic material. In one embodiment, the layer of patterned optically anisotropic material is fabricated in the form of patterned, optically anisotropic liquid crystal polymer. In another embodiment, the layer of patterned optically anisotropic material is a layer of liquid crystal, the diffractive waveplate diffuser also includes two alignment layers and two transparent conductive coatings, and the properties of the liquid crystal layer are controlled by the application of an electric potential between the two transparent conductive coatings. A method is provided for designing the alignment pattern of the layer of optically anisotropic material.

Electro-optical diffractive waveplate beam shaping system

Mirrors, lenses, devices, apparatus, systems and methods for correcting temporal dispersion of laser pulses or other pulses of electromagnetic radiation in diffractive telescopes used in applications, such as but not limited to optical telescopes, transmitters, receivers, and transceivers for laser communication and imaging. Diffractive lenses and mirrors allow for producing large area telescopes and reducing or eliminating temporal dispersion of laser pulses and other pulses of electromagnetic radiation recorded by such telescopes. This can be achieved by utilizing high efficiency thin film diffractive optical films, particularly, diffractive waveplates, and having a secondary diffractive mirror of a shape selected to assure that the propagation time from the flat primary collecting lens or mirror is independent of the position on the flat primary collecting lens or mirror at which the radiation impinges.

Diffractive mirrors and diffractive telescopes with corrected temporal dispersion

Optical lenses, systems, devices and methods for fabricating and manufacturing diffractive waveplate lenses that allow setting the focal length sign of an optical system by positioning the lens with its front or back surface with respect to an incoming circular polarized light beam. Applications for the lenses include optical systems comprising fibers, diode lasers, waveplates, polarizers, and variable lenses, particularly, in the form of a set of polymer films with re-attachable adhesive layers. And providing a flat mirror with concave or convex function due to diffractive waveplate lens coating.

Energized lens systems and methods of fabricating an energized lens system which can be switched from one polarization-independent focal length to another polarization-independent focal length. The energized lens system can include a 90 degree twisted nematic liquid crystal layer with curved boundaries, and with transparent conductive electrodes which allow the application of an electric field to switch the focal length of the twisted nematic liquid crystal layer. The focal length of the energized lens system can be independent of the polarization of light in both of its two states, and only one liquid crystal layer of the energized lens system needs to be switched in order for the focal length of the energized lens system to be switched.

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Apopka, FL, United States of America

David E Roberts