Abstract: A satellite constellation has a plurality of network satellites that form a network. A gateway satellite is disposed adjacent to the network. The gateway satellites receive an optical signal from the network and converts the signal to an electrical signal. The gateway satellite has a sorter and a reshaping circuit for reshaping the electrical signal to form a reshaped signal. The electrical signal is converted back to an optical signal corresponding to the reshaped signal. The optical signal corresponding to the reshaped signal has reduced noise in comparison to the input optical signal. The optical signal is then retransmitted to another satellite.

Abstract: A free space optical bus system and method are provided for connecting two units of circuitry across a free space gap. A first unit of circuitry includes a multiplexer that combines a plurality of bus signals to obtain an electronic combined signal and a laser that is driven by the electronic combined signal to transmit an optical signal. A second unit of circuitry is separated from the first unit of circuitry by a free space gap. The second unit of circuitry includes a photodetector that receives the optical signal and transforms it into an electronic composite signal and a demultiplexer that divides the composite signal into a plurality of constituent signals.

Abstract: A technique for synchronizing the servo control systems between two optical wireless links (OWLs) that are in communication with one another. This synchronization allows the alignment in time of the various tasks to be assigned in a desired time period. The synchronization is not intended to synchronize the two OWLs down to the processor clock level, but rather at the servo sampling level, preferably to within a few percent of the servo sampling time. This synchronization may be advantageous in improving processor efficiency and control loop performance, and or improving system calibrations.

Abstract: A communications system for wireless transceiving of information, comprising an optical array subsystem for transceiving optical signals and a millimeter wave subsystem for transceiving millimeter wave signals, and a beam steering controller for controlling the direction of the optical and millimeter wave signals. The communication system may be on a flying platform, such as a satellite and may communicate with multiple remote terminals.

Abstract: A communication system employing optical fibers and a high data rate satellite is utilized to provide high-speed Internet access to various geographic regions. In one aspect, a first teleport station is located geographically separated from a first user. The first teleport station is connected through a network access point to the Internet. The second user communicates through a satellite to the first teleport station to access the Internet. The teleport station and the network access point use a long haul optical fiber.

Abstract: Apparatus, and a corresponding method, for spatially isolating a transmit beam and a receive beam, which, in satellite communication systems, are inherently separated by a look ahead angle. A receive beam separation mirror is positioned in the receive beam path but out of the transmit beam path, and the receive beam is reflected along a path separated from the transmit beam path. The mirror may be annular, allowing the transmit beam to be directed through the center of the mirror. In applications where a desired isolation angle is different from the look ahead angle, or where there is no look ahead angle, the receive beam separation mirror is used in conjunction with a dichroic beam splitter and at least one receive beam steering mirror, to achieve the desired angular separation.

Abstract: An antenna system for receiving both RF wave and optical wave radiation via a single antenna aperture that may be moved between stowed and deployed configurations as needed. The system includes a wavefront correction system for correcting optical wavefront distortion errors caused by anomalies in the shape of the antenna aperture itself, as well as optical wavefront distortion errors caused by atmospheric perturbations. The optical components used for optical signal conditioning are supported from the antenna aperture and form a compact, unobtrusive means for separating electromagnetic and optical wave signals received by the antenna aperture.

Abstract: A communications terminal includes a first aperture configured to receive laser signals from ground laser sources, pick-off mirrors configured to receive laser signals from mobile laser sources, an optical assembly configured to receive the laser communications signals from ground laser sources and mobile laser sources, wherein the optical assembly is configured to focus laser signals onto a common focal plane, and laser receivers located at the focal plane configured to receive laser signals from at least one laser source at a time.

Abstract: A laser communications system includes a wide-field sensor, configured to detect a first set of laser communications sources within a first field of view, a narrow-field sensor includes a tracking portion and a control portion configured to receive laser communications from a second set of laser communications sources within a second field of view, wherein the first field of view is larger than the second field of view, and wherein the second set of laser communications sources comprises at least a first source and a second source, and a redirection unit coupled to the narrow-field sensor configured to position the second field of view within the first field of view wherein the first receiving element is positioned in response to the first positioning signal for the first receiving element, and the second receiving element is positioned in response to the first positioning signal for the second receiving element.

Abstract: An optical communication system is provided which includes an optical signal transmitter which communicates high bandwidth, high power frequencies. The optical signal transmitter includes a high efficiency/high power optical source such as an optical magnetron or a phased array source of electromagnetic radiation, and a modulator element. The modulator element may be within a resonance cavity of the high efficiency/high power optical source (intra cavity) or external to the cavity (extra cavity). The modulator element serves to modulate output radiation of the high efficiency/high power optical source to produce a modulated high frequency optical signal which may be transmitted through the air. The optical signal transmitter is particularly useful in providing the last mile connection between cable service operators and end users.

Abstract: Exemplary embodiments of the present invention include a method for navigating a UAV. Such embodiments include receiving in a remote control device a user's selection of a GUI map pixel that represents a waypoint for UAV navigation. The pixel has a location on the GUI. Such embodiments also include mapping the pixel's location on the GUI to Earth coordinates of the waypoint, transmitting the coordinates of the waypoint to the UAV, reading a starting position from a GPS receiver on the UAV, and piloting the UAV, under control of a navigation computer on the UAV, from the starting position to the waypoint in accordance with a navigation algorithm.

Abstract: The invention relates to a system for conveying digital signals inside a space vehicle between a transmitter and a receiver. In the invention, the link between the transmitter and the receiver comprises a first portion made of optical fiber and a second portion in which infrared radiation propagates without guidance. A particular application lies in conveying remote control and telemetry signals within a satellite between a control module and a piece of equipment.

Abstract: An optical transceiver having a transmitter section and a receiver section formed on a substrate to be close to each other is provided, which suppresses the electrical and optical crosstalk between the transmitter section and the receiver section. The transceiver comprises: (a) a substrate; (b) a transmitter section formed on the substrate and including a light-emitting element; (c) a receiver section formed on the substrate to be close to the transmitter section and including a light-receiving element; (d) a conductive first connection member fixed near the substrate; and (e) a transparent second connection member fixed near the first member in such a way as to block the first opening and the second opening of the first member from a front of the first member. The first member has a first opening that allows a first light beam to penetrate the first member and a second opening that allows a second light beam to penetrate the first member.

Abstract: The invention relates to a communications backbone interface between at least three members of a communications network for a space vehicle. In the invention, the interface combines various signals received at inlets, which signals may be analog, digital, and optical, coming from two members, and produces a multiplexed optical signal for delivery to a member of the vehicle, such as a piece of equipment. The invention also provides to a communications terminal interface, a communications network having such interfaces, and an optical fiber harness.

Abstract: A MEMS-based optical, wireless communication system (10) that is comprised of a receiving and transmitting optical unit (12) that is further comprised of a transmitting subsystem (14) and a receiving subsystem (60), both of which are controlled by a microcontroller (16) and firmware (96). The system (10) is designed to allow a first unit (12) to transmit through free space a modulated laser beam (39) that is received by a second unit (12) located within line-of-sight of the first unit (12). Conversely, the second unit (12) can likewise transmit a modulated laser beam (39) that is received by the first unit (12) or other line-of-sight units (12). The system (10) features a MEMS mirror assembly (34) that operates in combination with a quad sensor (100). The combination allows fast, precise tracking and compensates for atmospheric disturbances associated with optical communication namely, building sway, wind and scintillations caused by changes in the refraction index of the atmosphere.

Abstract: A system and method for efficiently and effectively simulating hardware-in-the-loop testing of a wireless communications network. The system and method employs an optical matrix-vector multiplier (MVM) for performing optical signal processing to simulate radio frequency (RF) signal propagation characteristics in a mobile wireless communications network. Specifically, the system and method employs an optical modulator, which is adapted to modulate optical energy with signal energy, such as radio frequency (RF) signal energy, propagating from a first group of transceivers of the network to form a vector of optical signals. The optical matrix-vector multiplier (MVM) receives the vector of optical signals, and has a matrix of optical channel weights which are modifiable in accordance with desired parameters to represent at least on parameter of the wireless network. The optical MVM is further adapted to output signals based on the received vector of optical signals and the optical channel weights.

Abstract: A node for use in a wireless communication network that facilitates alignment of the node with other nodes in the network and a method for aligning the node. The node includes mounting fixtures that enables the mounting of GPS receivers and a tiltmeter to obtain position and bearing information for the node. The node contains alignment features that enable the positioning of an optical transmitter/receiver pair in the node using the data obtained from the GPS receivers and tiltmeter.

Abstract: A system and method for optical wireless communication with fading resistance. A delayed diversity approach reduces fading significantly. Data is sent in a set of light signals (also called diverse light signals) which each have a different polarization and/or a different wavelength. The diverse light signals are also temporally different in that they are transmitted in a delayed fashion with respect to one another. In this way, each light signal is carried over a different, uncorrelated “channel” through the atmosphere. At a receiver, original data in each received light signals is temporally adjusted and combined into a single output data signal. The accuracy of each bit in the output data signal is then due to the reception of the combined diverse light signals.

Abstract: A satellite constellation has a plurality of satellites. Each of the satellites has an RF ground link for communicating with a ground station and an optical link for communication with at least one of the plurality of satellites. Each of the satellites has a reconfigurable optical transmitter for sending and receiving data streams. Each reconfigurable optical transmitter has a first optical carrier associated therewith and a reconfigurable optical receiver. The plurality of satellites is arranged to have a first subset of satellites. The first subset of satellites is configured to communicate. The plurality of satellites is reconfigured to have a second subset of satellites having at least one different satellites than that of said first subset. The second subset supercedes the first subset. The second subset of satellites is configured to communicate. Various subset around the globe may form local area networks. The local area networks are preferably optically coupled to form a wide area network.

Abstract: In one embodiment of the invention, a first absorbing layer is on a substrate and/or a second absorbing layer is on a heat-activated adhesive. If the IR source that supplies IR radiation is present on the substrate-side, then the absorption percentage of the substrate is less than the absorption percentage of the first absorbing layer if present and less than the absorption percentage of the second absorbing layer if present. If the IR source that supplies IR radiation is present on the “encapsulation cover”-side, then the absorption percentage of the encapsulation cover is less than the absorption percentage of the first absorbing layer if present and less than an absorption percentage of the second absorbing layer if present. The substrate and the encapsulation cover have a low thermal conductivity.

Abstract: An optical communication system using a high altitude tethered balloon 10 that operates above most clouds and atmospheric turbulence. An optical communication system includes a balloon 10 with an optical communication payload 30, a fiber optic cable attached to the tether 12, an automated winch system 14, and a ground station 28. The balloon 10 is designed for sustained flight at, and recovery from, high altitude using the automated winch system 14. An acquisition, tracking and pointing (ATP) system 22 enables a balloon-based optical transceiver 24 to maintain line-of-sight optical communications with an overhead satellite 34. The optical link between the satellite 34 and the balloon 10 is an open channel. Data is transmitted to the ground station 28 from the balloon 10 through the secure fiber optic closed channel attached to the tether 12.

Abstract: Internal communication signals in a stored program controlled system comprising a plurality of units configured to process signals are provided by a free space optical beam line which is proximal to all of the plurality of units. The free space beam line is configured to contain optically encoded signals which comprises signals transmitted between and/or among the plurality of units. Each unit includes a probe for injecting optically encoded signals in the free space beam line and/or and for receiving optically encoded signals from the free space beam line. Advantageously, there may be a first terminal at a first end of the beam line to configure to transmit and terminate the optically encoded signals and a second terminal unit at the second end of the free space beam line configured to transmit and terminate the optically encoded signals.

Abstract: An optical transceiver includes an opaque element having a concave reflective surface arranged in a path of each of an outgoing and an incoming light signal, the reflective surface configured to redirect the paths of the respective light signals. An optical detector is arranged facing the reflective surface. The optical detector is configured to detect a redirected incoming light signal from the reflective surface and to generate therefrom a receive signal proportional to the incoming light signal. An emitter is arranged facing the reflective surface. The emitter is configured to generate the outgoing light signal proportional to a transmit signal. A lens assembly is arranged between the reflective surface of the opaque element and both the optical detector and the emitter. The lens assembly is configured to couple the redirected incoming light signal to the optical detector and to couple the outgoing light signal to the reflective surface.

Abstract: An infrared detection system for seeing multiple pixel scenes and/or connecting multiple detectors, within each communications path, includes a data processor, optical toggles and/or electrical switches, and a large number of pixels and detectors. For the spatial net, the data processor sends signals to the optical toggle and electric switches connecting neighboring pixels and other detector elements to the data processor. A single communications path serves several pixels and detector elements thereby minimizing interconnection congestion from the pixels to the processing circuitry.

Abstract: An optical inter-satellite link (OISL) gimbal 10 that is particularly suited for directing an optical beam in an optical inter-satellite communications system is disclosed. The OISL gimbal 10 includes an azimuth drive housing 20, a generally cylindrical azimuth shaft 22 rotatably connected to the azimuth drive housing 20 and an optical payload 210 or beam-steering mirror 70 rotatably connected to the azimuth shaft 22. The azimuth shaft 22 has a clear aperture through which one or more optical beams may be directed to and from a stationary optical payload 30. A capacitive azimuth position sensor 40 detects the rotational position of the azimuth shaft 22 and a direct drive azimuth motor 50 drives rotation of the azimuth shaft 22. The OISL gimbal 10 preferably provides two-axis rotation of the optical payload 210 or beam-steering mirror 70 through approximately +/?180 degrees of inboard (azimuth) travel and +/?30 degrees of line-of-sight outboard (elevation) travel.

Abstract: Integrated glass ceramic spacecraft include a plurality of glass ceramic components including molded, tempered, annealed, and patterned glass ceramic components coupled together for forming a support structure or frame or housing through which is communicated optical signals through an optical communications grid and electrical signals through an electrical communications grid, with the optical communications grid and electrical communication grid forming a composite electrooptical communications grid for spacecraft wide intercommunications. The support structure multifunctions as a frame, a housing, a support, a thermal control system, and as part of an electrooptical communications grid while encapsulating a plurality of optical, electronic, electrical, and MEMS devices between which is communicated the electrical and optical signals over the electrooptical communication grid.

Abstract: A beacon beam is transmitted from a receiver to a transmitter. The transmitter generates and transmits a conjugate beacon beam back to the receiver, where it is interfered with a local oscillator beam to form a hologram. The hologram is used to configure a spatial light modulator as a diffraction grating. A conjugate communications laser beam containing information is subsequently transmitted to the receiver. The diffraction grating deflects the conjugate communications beam to a fixed and known direction, whereupon it is directed through a spatial filter. Since the direction of the conjugate communications beam is fixed and known, the diameter of the filter aperture can be minimized to accept the communications beam while rejecting almost all of the background light. A high-speed detector directly detects the filtered conjugate communications beam. The detector output is transmitted to a demodulator that extracts the information carried by the communications beam.

Abstract: A window-mounted positionable collector comprising a base that is secured to a window. An inner rotatable hollow wedge-cut member may be rotated about the base to produce a first degree of freedom, while an outer rotatable hollow wedge-cut member may be rotated about a top end of the inner rotatable hollow wedge-cut member to provide a second degree a freedom. The combination of the first and second degrees of freedom enables the optical axis of an optical collector operatively coupled to the outer rotatable hollow wedge-cut member to be directed along any direction falling within a cone of angulation defined by acute angles corresponding to the angles of the wedge cuts defined in the rotatable hollow wedge cut members. In one embodiment, a cover is connected to a top end of the outer rotatable hollow wedge-cut member to form a sealed volume, whereby the apparatus may be secured to the window by applying a vacuum to the sealed volume.

Abstract: Optical wireless links automatically align themselves using feedback information that is transmitted over the light beams being aligned. Each link performs an acquisition routine in which its light beam is swept through a pre-defined pattern while transmitting its beam alignment information. When a link receives beam alignment information from a remote link, it updates its transmission to include the alignment information received from the remote link. At some point during the acquisition routine, the remote link will receive its own alignment information “echoed back” from the first link and will re-align its beam accordingly. At some point, each link will have received its own alignment information echoed back from the other link and will have aligned itself to that position. Data communication can begin at that point, or a more refined alignment step can then be performed. The alignment information can be based upon position, sample number, or time transmitted.

Abstract: A wireless atmospheric site-to-site full-duplex (i.e., simultaneous transmit and receive) laser communication system, typically for wideband (high-speed) data, voice, and/or video transmission. The system includes at least one laser communication transceiver each having an electro-optical transmitter that includes a laser source for generating laser light to be transmitted site-to-site and at high speed, an electro-optical receiver that includes a baffle assembly for receiving light directly onto a detector, without an intermediate field stop and re-imaging relay optics to reject off-axis light sources. Wideband data are transmitted and received through the atmosphere by the electro-optical transmitter and the electro-optical receiver. The data to be transmitted through each laser communication transceiver is inputted through a fiber-optic receiver and outputted by a fiber-optic transmitter.

Abstract: A laser crosslink apparatus includes an optical device (212, FIG. 5), a beam splitter (512), an acquisition channel and a tracking and communication channel. The acquisition channel includes a high density optical fiber bundle and an acquisition channel device (510). The optical device (212) receives laser light from a wide field of view, and the beam splitter (512) splits the light into the two channels. The high density optical fiber bundle (204) has one end (206) in a focal plane of the optical device, and another end (208) coupled to the acquisition channel device (510). The acquisition channel device (510) includes an optical receiver array (400, FIG. 4). The location of spot footprints on the optical receiver array determines the direction from which the laser light is received within the wide field of view.

Abstract: A method and an arrangement for the employment of free space transmission systems for interruption-proof links between individual satellites of satellite communications systems by utilizing optical terminals. The communication link between two satellites is established in a reliable manner despite the presence of microvibrations.

Abstract: A satellite constellation has a plurality of network satellites that form a network. A gateway satellite is disposed adjacent to the network. The gateway satellites receive an optical signal from the network and converts the signal to an electrical signal. The gateway satellite has a sorter and a reshaping circuit for reshaping the electrical signal to form a reshaped signal. The electrical signal is converted back to an optical signal corresponding to the reshaped signal. The optical signal corresponding to the reshaped signal has reduced noise in comparison to the input optical signal. The optical signal is then retransmitted to another satellite.

Abstract: A satellite constellation has a plurality of network satellites that form a network. A gateway satellite is disposed adjacent to the network. The gateway satellites receive an optical signal from the network and converts the signal to an electrical signal. The gateway satellite has a sorter and a reshaping circuit for reshaping the electrical signal to form a reshaped signal. The electrical signal is converted back to an optical signal corresponding to the reshaped signal. The optical signal corresponding to the reshaped signal has reduced noise in comparison to the input optical signal. The optical signal is then retransmitted to another satellite.

Abstract: A system in which a personal computer sends messages into a TCP/IP network using a conventional dial-up link and downloads data from the TCP/IP network using a high-speed one-way satellite link. A preferred embodiment uses a conventional SLIP provider to connect to the TCP/IP network and uses a commercial software TCP/IP package that has a standard driver interface. A spoofing protocol compensates for the long propagation delays inherent to satellite communication.

Abstract: This invention describes an optical communications system for optically networking computers and other devices together in a multi-user environment in a cost effective manner. This is accomplished through the use of low power (eye safe intensity) lasers, light emitting diodes, or photo diodes, to connect users in a time shared fashion through an optical multiplexing system (the optical access point) which can direct and manage the networking connection to each user device (user optical transceiver) independently. Both the optical access point and the user optical transceiver are capable of dynamically adjusting a beam to locate and align with each other.

Abstract: A spacecraft data acquisition system comprises a telemetry and command controller, a payload unit, and a bi-directional interface that couples the telemetry and command controller to the payload unit. The interface is a single bi-directional interface that is used to reduce the complexity of the spacecraft. The transmission of information over the interface has a predetermined protocol so that the telemetry and command controller and payload unit may effectively use the single interface.

Abstract: A free space laser communication system that maintains dynamic alignment is presented. The system comprises two laser transceivers positioned a distance apart. Each transceiver includes the following components. A beacon laser is provided for transmitting a beacon beam at a first wavelength in a beam having a first divergence. A signal laser is provided for transmitting a signal beam carrying information to be transmitted to the other transceiver. A special telescope system is provided for collecting both the incoming beacon beam and the incoming signal beam from the other transceiver and for transmitting at least an outgoing signal beam. In a preferred embodiment the special telescope images the pupil of the telescope onto a tracking mirror. The tracking mirror pivots at least tilt and tip.

Abstract: The present invention provides photonic devices utilized in optical telecommunications. The photonic devices include photosensitive bulk glass bodies which contain Bragg gratings, particularly with the ultraviolet photosensitive bulk glass bodies directing optical telecommunications wavelength range bands. Preferably the ultraviolet photosensitive bulk glass bodies are batch meltable alkali boro-alumino-silicate bulk glass bodies. One embodiment of the invention relates to an optical element including a transparent photosensitive bulk glass having formed therein a non-waveguiding Bragg grating; and a optical element optical surface for manipulating light. Desirably, the photosensitive bulk glass has a 250 nm absorption less than 10 dB/cm.

Abstract: According to an exemplary embodiment of the present invention, an optical waveguide and method of use includes a grating which has a grating parameter that is adapted for dynamically variable non-uniform alteration. The non-uniform alteration of the grating parameter results in the introduction of a predetermined amount of chromatic dispersion and dispersion slope into an optical signal traversing the waveguide. According to another exemplary embodiment of the present invention, an optical apparatus and method of use includes a plurality of optical waveguides each of which have an optical grating and at least one of the waveguide gratings has a grating parameter that is adapted for dynamically variable non-uniform alteration. The optical apparatus further includes a device, which dynamically varies the grating parameters of each of the waveguides to selectively introduce chromatic dispersion and dispersion slope into an optical signal traversing the apparatus.

Abstract: A partially configurable optical add/drop multiplexer (OADM) is provided. Fixed single channel and wideband tunable fiber Bragg gratings may be used in combination. OADM channel configuration may be changed by tuning one or more tunable fiber Bragg gratings.

Abstract: A system for communicating signals over a satellite makes more efficient use of bandwidth compared with conventional systems. In one embodiment, the system converts an optical signal having a first bit-rate format into a plurality of signals, each having a bit-rate format smaller than the first bit-rate format and thus smaller transmission bandwidths than the initial optical signal. The converted signals are then modulated and transmitted to a satellite over a predetermined frequency band. The satellite includes a first transponder having an operating bandwidth substantially equal to the transmission bandwidth of at least two of the transmitted signals, and a second transponder having an operating bandwidth sufficient to receive remaining ones of the transmitted signals. In one preferred embodiment, the higher bit-rate format signal is an OC-3 signal, the lower bit-rate format signals are OC-1/STS-1 signals, and the first and second satellite transponders have 36 MHz operating bandwidths.

Abstract: A multireflector fiber optic filter apparatus, wherein the transmittance and reflectance spectra are periodic in frequency, the apparatus comprising an etalon with N equally spaced reflectors wherein the transmittance and reflectance spectra of said etalon are periodic in optical frequency with a period given by the formula: &Dgr;&ngr;FSR=c/(2ngL), where c=the free space speed of light; ng=the group refractive index for the light propagating in the medium between the reflectors, L=separation between said reflectors, and N is an integer=3,4,5, . . . In a further aspect, an optical circulator is connected to the etalon and an optical fiber is connected to the optical circulator for reflected output.

Abstract: A plasma antenna is provided having an ionizer, which when energized, generates a bounded or unbounded plasma column extending along a vertical axis. When ionization is initiated, the difference in the diffusion characteristics of ions and electrons and the resulting gas plasma produce a current pulse in a first direction. As the plasma extinguishes, the difference in relaxation times for the ions and electrons in the plasma produces a second current pulse of opposite direction. The alternating current pulses generate an electric field that radiates from the plasma column.

Abstract: A communications system for wireless transceiving of information, comprising at least one multiple beam scanning array transceiver located in a satellite for wirelessly transceiving the information; and at least two terminals at diverse locations capable of wirelessly transceiving the information between the terminals and the satellite. The multiple beam scanning array transceiver can be optically based, and contain micro-mirrors or optical switches. Also disclosed is an apparatus for determining atmospheric conditions for use in adjusting the multiple beam scanning array transceiver parameters.