Abstract: Embodiments disclosed herein address these and other issues by providing a retro-modulating optical “tag” with a wide FOV that enables high-speed communication in a compact design. Embodiments enable retro-modulation via a lens assembly that directs light to a reflective surface, through a Quantum Well Modulator (QWM) that modulates the light. A wide field of view can be achievable, for example, using a lens with a high index of refraction, which may be optically contacted with the QWM.

Abstract: A scintillation based imaging system. The device utilizes a single-crystal inorganic scintillator to convert ionizing radiation to light in a spectral range or ranges within the visible or ultraviolet spectral ranges. The conversion takes place inside the single crystal material, preserving special resolution. The single crystal scintillator is sandwiched between a first plate that is substantially transparent to the ionization radiation and a second plate that is transparent to the visible or ultraviolet light. The ionization radiation is directed from the submicron source through a target to create a shadow image of the target inside the scintillator crystal. Several sources of radiation are described.

Abstract: A scintillation based imaging system. The device utilizes a single-crystal inorganic scintillator to convert ionizing radiation to light in a spectral range or ranges within the visible or ultraviolet spectral ranges. The conversion takes place inside the single crystal material, preserving special resolution. The single crystal scintillator is sandwiched between a first plate that is substantially transparent to the ionization radiation and a second plate that is transparent to the visible or ultraviolet light. The ionization radiation is directed from the submicron source through a target to create a shadow image of the target inside the scintillator crystal. Several submicron sources of radiation are described. These include submicron x-ray and high-energy ultraviolet sources, submicron electron beam sources, submicron alpha particle sources, submicron proton sources, submicron positron sources and sub-micron neutron sources.

Abstract: A polarizing multiplexer includes a first arm with a first beam splitter to receive a first unpolarized light from an object and a first retarder coupled to the first beam splitter to generate a first right-hand circularly polarized (RHCP) beam. A normal incident beam splitter is used to receive the first RHCP beam. The multiplexer also includes a second arm with a second beam splitter to receive a second unpolarized light from an object; and a second retarder coupled to the second beam splitter to generate a left-hand circularly polarized (LHCP) beam, wherein the LHCP beam is reflected off the normal incident beam splitter and converted to a second RHCP beam. Light from both arms pass through the second retarder and are converted to p-polarized light before transmitting through the second beam splitter to an image sensor.

Abstract: A photonic switch includes an array of waveguides (optical fibers) that are rigidly mounted together and arranged as a matrix. One waveguide acts as an input for the switch, and is used to transmit a light beam into free space. The other waveguides then function individually as outputs for the switch. Operationally, a switch connection is made by moving a steering mirror to direct the light beam from the input waveguide to a selected output waveguide. For one embodiment, the mirror is flat. For this embodiment the switch incorporates a collimating lens positioned between the array and the mirror, with the mirror at the telecentric stop of the lens. In another embodiment, the mirror has a concave surface.

Abstract: An actuator for moving the steering mirror of an optical switch is manipulated during the operation of the switch to route light beams along selected paths through free space. Structurally, the mirror has a reflecting surface area that is characterized by a largest dimension of less than fifteen millimeters, and the actuator defines a footprint within this area. The actuator includes a flexible universal pivot that is used to mount the mirror on a base member. The actuator also includes an electronic device that controls the magnetic interaction between a magnet on the mirror and a magnet on the base to selectively move the mirror on the universal pivot for the operation of the optical switch.

Abstract: Windows for infrared Mid-IR optical systems include thin film materials stretched over a rigid frame. The windows form a barrier between sensitive optics in an optic head and damaging elements of weather and environment. Windows and methods for making windows for free space optics communications systems include use of specialized materials and structural components to form durable inexpensive barriers in agreement with these inventions. Barriers can be used to provide protection of optics contained in an optical transceiver from an atmosphere composed of matter hostile to optics elements. The barrier can operate in conjunction with an enclosure housing to form a complete barrier between those optics and that atmosphere. These windows may be removable from the housing for replacement or maintenance. Advanced versions of these windows may also include specialized condensation prevention means.

Abstract: A photonic switch includes an array of waveguides (optical fibers) that are rigidly mounted together and arranged as a matrix. One waveguide acts as an input for the switch, and is used to transmit a light beam into free space. The other waveguides then function individually as outputs for the switch. Operationally, a switch connection is made by moving a steering mirror to direct the light beam from the input waveguide to a selected output waveguide. For one embodiment, the mirror is flat. For this embodiment the switch incorporates a collimating lens positioned between the array and the mirror, with the mirror at the telecentric stop of the lens. In another embodiment, the mirror has a concave surface.

Abstract: An actuator for moving the steering mirror of an optical switch is manipulated during the operation of the switch to route light beams along selected paths through free space. Structurally, the mirror has a reflecting surface area that is characterized by a largest dimension of less than fifteen millimeters, and the actuator defines a footprint within this area. The actuator includes a flexible universal pivot that is used to mount the mirror on a base member. The actuator also includes an electronic device that controls the magnetic interaction between a magnet on the mirror and a magnet on the base to selectively move the mirror on the universal pivot for the operation of the optical switch.

Abstract: A liquid crystal variable retarder (LCVR) with automatic gain control for use with an imager-based target tracking application such as a free-space laser communication system. An LCVR is made of two optical windows separated by a gap, typically of a few microns. The gap is filled with nematic liquid crystal material. Electrodes are situated to enable an electric field to be applied between the optical windows and thus across the liquid crystal material. With no voltage applied to the electrodes the liquid crystals lie parallel to the optical windows. In this state of operation, the LCVR exhibits maximum retardation. As voltage is applied to the electrodes the liquid crystal molecules rotate away from the optical windows, becoming perpendicular to the optical windows. In this state of operation, the LCVR exhibits minimum retardation.

Abstract: A free-space laser communication system having six axes of movement. The system includes a fine tracking and acquisition system comprising a low inertia steering mirror having two axes of movement which points the communication laser transmission optical apertures separately from the optical apertures for the beacon laser, a coarse tracker, and a communication receiver. A fine tracking centroider and the communication lasers have the steerable mirror in common, and thus do not experience any alignment error that might arise from use of a separate deflecting element for each. The fine tracking and acquisition system is preferably mounted on a gimbal having two axes of movement, and the gimbal in turn is preferably mounted in a housing having two axes of movement.

Abstract: An optical collimating device employs an optical (concave) mirror and cholesteric liquid crystal element to collimate and project image light into the line-of-sight of an observer in efficient manner. Image light is generated with light components within a predetermined bandwidth and with a predetermined rotary sense. The image light is directed so that it is reflected by the concave mirror, expanding (collimating) the image light, projecting in onto a cholesteric liquid crystal element that reflects those components of the image light within the bandwidth B and having the proper rotary sense of circular polarization. The cholesteric liquid crystal element substantially reflects the returned image to the observer.