Abstract: A modular free space optical (FSO) communications device may include an adaptive optics (AO) module and an interchangeable optical relay (OR) module. More particularly, the AO module may include an AO housing and at least one AO device carried thereby. Also, the interchangeable OR module may include an OR housing and at least one OR device carried thereby. The at least one OR device of a given OR module may provide a predetermined focal length range from among different focal length ranges for respective OR modules. In addition, the OR housing and the AO housing may be interchangeably connectable and establish an optical path between the at least one OR device and the at least one AO device when connected.

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: An optical-axis directional indicating apparatus for optical communication includes a photoreceptor having a light-receiving surface and a plurality of optical receiving elements arranged on the surface in a first direction and a second direction orthogonal to the first direction, to receive a transmitted light beam, a detector to detect levels of the light beam received at the optical receiving elements, a plurality of display elements arranged in the first and second directions so as to correspond to the optical receiving elements of the photoreceptor, and a switch circuit to selectively turn on or off the display elements in accordance with the levels of the light beam detected by the detector, to indicate whether or not an optical axis of the light beam is deviated in the first and/or the second direction on the light-receiving surface of the photoreceptor.

Abstract: A free space optics communication apparatus is provided which allows flexible setting in accordance with the number or distances of other apparatuses in single-to-multipoint communication. The free space optics communication apparatus has a movable mirror array which has a plurality of mirrors capable of reflecting a light signal from a light source and arranged in a matrix-like form, and a mirror control circuit for controlling the directions of the respective mirrors to form a plurality of mirror groups which reflect the light signal toward the other apparatuses in the movable mirror array. The number of the mirror groups formed in the movable mirror array through the control of the directions of the mirrors by the mirror control circuit is changeable.

Abstract: A digital data network uses network nodes incorporating infrared transceivers. Each node includes a plurality of infrared transceivers having transmitter and receiver optics designed to facilitate line-of-sight infrared optical communications in a residential or business neighborhood. New nodes are installed with at least one selected transceiver having line-of-sight access to at least one existing transceiver. Automated tracking and acquisition processes are used to align transceivers to enable data communication and to acquire newly installed nodes into the network. Other automated tracking programs operate on an as-needed or scheduled basis to maintain good alignment and communications between adjoining node transceivers. Network nodes include weather-proof housings and are of a size and shape to be easily mounted on existing structures so as not to disrupt the visual appeal of a neighborhood.

Abstract: A modular free space optical (FSO) communications device may include an optical relay (OR) module and a base module. More particularly, the OR module may include an OR housing and at least one OR device carried thereby. Further, the base module may include a base housing and at least one positioner carried thereby for providing relative movement between the base module and the OR module for optical beam aiming. The modular FSO communications device may also include a camera and a remote station interface connected to the at least one positioner for permitting remote optical beam aiming. Furthermore, the remote station interface may also be connected to the camera for permitting remote viewing.

Abstract: An optical transceiver is equipped with at least one coupling lens which condenses reception signal light from an optical medium and condenses transmission signal light to the optical medium, an optical plate which passes the reception signal light and reflects the transmission signal light, a light receiving element which receives the reception signal light passed through the optical plate, and a light emitting element which transmits the transmission signal light so as to be reflected by the optical plate, wherein an emission port of the transmission signal light of the light emitting element is arranged at a position to enable the transmission signal light from the light emitting element to form an image in the optical medium via the optical plate and the coupling lens, and wherein the emission port of the transmission signal light of the light emitting element is arranged in a direction that makes the incident angle formed on the optical plate by the beam center line of the transmission signal light trans

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: In a disclosed spatial optical communication apparatus, the optical-axis deviation correction is possible at the same time for both high-speed angular variation with a small amplitude and low-speed angular variation with a large amplitude, and the apparatus has a function of correcting the optical-axis deviation whose application range is wide and whose correction ability is high. To achieve such function, the spatial optical communication apparatus for performing communication between spaced locations with a light beam is provided with both a light deflecting unit set inside an optical system with a narrow variable angle range and a fast response speed, and an optical system driving unit set outside the optical system with a slow response speed and a wide variable angle range.

Abstract: A free space optics communication apparatus which achieves high use efficiency of light and enables free control of the divergent angle of a light beam and the like is disclosed. The free space optics communication apparatus of the present invention has a light source which emits a light beam for performing wireless communication of information, and a minute mirror array unit which consists of a plurality of minute mirrors arranged in a matrix-like form and reflects the light beam emitted from the light source toward another apparatus. The apparatus also has a control unit which controls the directions of the individual minute mirrors constituting the minute mirror array unit independently. The control unit may be used to variably control the number of a plurality of mirror groups formed of a plurality of the minute mirrors in the minute mirror array unit.

Abstract: An optical head is provided for a free space optical communications system. The optical head is utilized for transmitting and receiving modulated infrared laser beams. The optical head includes an optical amplifier, a circulator, an ultrafine-steering element, a fine-steering element, a course-steering element, and a fine track sensor. Additionally, a method is provided for facilitating airborne free space optical communications between an airborne host platform and a link platform. Each platform has an optical head which transmits and receives data via modulated infrared laser beams, wherein the host includes at least an optical head having a fine, coarse, and ultrafine steering element configured in a cascaded three-tier steering element architecture.

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: A transceiver for a through-air optical communications system and the related method for transmitting signals through air by utilizing coherent light beams. The transceiver according to the invention comprises a receiving reflecting surface to properly reflect the coherent light received from another transceiver, said receive surface defining an outer edge. The transceiver is characterized by further comprising a single aperture in the shape of an annulus to pass the coherent light to be transmitted, said aperture substantially extending close to the outer edge of the receiving surface. Conveniently the annulus-shaped aperture is formed in the same main disk in which the receive reflecting surface is realized. The problem of scintillation and alignment between receiving and transmitting parts of the transceiver is reduced.

Abstract: A microlens assembly is automatically aligned (positioned) to facilitate optimal light beam transmission between two spaced-apart subsystems (e.g., two printed circuit boards) supported within a larger system (e.g., a server system). The microlens assembly is controlled by the first subsystem, which also includes a light source (e.g., an emitter array) that generates the light beams by converting data signals. The second subsystem is provided with a receiver capable of receiving the light beams from the light source. The microlens assembly manipulates the microlens according to a raster light beams over a wide area surrounding the second subsystem. The optimal position of the microlens is determined by measuring a strength of each light signal, and by identifying an optimal strength light signal. The microlens assembly is then locked into the position associated with the optimal light signal.

Abstract: A digital data network uses network nodes incorporating infrared transceivers. Each node includes a plurality of infrared transceivers having transmitter and receiver optics designed to facilitate line-of-sight infrared optical communications in a residential or business neighborhood. New nodes are installed with at least one selected transceiver having line-of-sight access to at least one existing transceiver. Automated tracking and acquisition processes are used to align transceivers to enable data communication and to acquire newly installed nodes into the network. Other automated tracking programs operate on an as-needed or scheduled basis to maintain good alignment and communications between adjoining node transceivers. Network nodes include weather-proof housings and are of a size and shape to be easily mounted on existing structures so as not to disrupt the visual appeal of a neighborhood.

Abstract: An optical communication unit has a pair of cable-side communication units provided for a full duplex communication system connected to each other with a pair of optical fiber cables, has apparatus-side communication units provided for full duplex communication system directly connected to the cable-side communication units respectively each to form a closest contact state therebetween, and provides controls for a speed to double speed in full duplex system by using an infrared ray IR between the closely contacted units.

Abstract: A method simultaneously aligns the two sets of optical wireless link transceiver mirrors such that light traverses a path from the transmitting laser off an outbound mirror, through free space, off the inbound mirror of the remote station, and finally onto the receiving element in the remote station.

Abstract: The present invention provides a method and apparatus for free-space optical communication. The method comprises the steps of receiving a receive optical beam through a narrow field of view, determining a receive power level, shifting an alignment, maximizing the receive power, and transmitting a transmit optical beam along the alignment, wherein the narrow field of view is less than a divergence of the transmit optical beam. The narrow field of view can be a narrow region of a multi-region field of view. The apparatus comprises an optical beam transmitter configured to generate a narrow diverging transmit beam, a narrow field of view optical receiver, wherein the field of view is less than the divergence of the transmit beam, and a controller configured to determine a power level of a receive beam and to determine adjustments to a direction of transmission maximizing receive power.

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: This invention provides a dynamic interconnection system which allows to couple a pair of optical beams carrying modulation information. In accordance with this invention, two optical beams emanate from transceivers at two different locations. Each beam may not see the other beam point of origin (non-line-of-sight link), but both beams can see a third platform that contains the system of the present invention. Each beam incident on the interconnection system is directed into the reverse direction of the other, so that each transceiver will detect the beam which emanated from the other transceiver. The system dynamically compensates for propagation distortions preferably using closed-loop optical devices, while preserving the information encoded on each beam.

Abstract: A hybrid wireless optical and radio frequency (RF) communication link utilizes parallel free-space optical and RF paths for transmitting data and control and status information. The optical link provides the primary path for the data, and the RF link provides a concurrent or backup path for the network data, as well as a reliable and primary path for the control and status information. When atmospheric conditions degrade the optical link to the point at which optical data transmission fails, the hybrid communication link switches to the RF link to maintain availability of data communications. The switch may occur automatically, based on an assessment of the quality of the optical signal communicated through the optical path.

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: A filtering technique for a free space communication that features encoding and decoding of signals employing a filtering apparatus that includes a bulk holographic transform function. Employing the encoding and decoding technique facilitates providing a great number of channels of communication in a unit volume while preventing unwanted cross-talk between the communication channels. In addition, secure communication links between transmitters and receivers may be provided.

Abstract: A receiving apparatus and transmitting apparatus capable of transmitting and receiving a high speed optical signal and a communication system using the same, including a transmitting apparatus having a conversion circuit for converting serially input data to a plurality of bits of parallel data given predetermined information and an LED array having a number of LED units corresponding to the number of bits of the parallel data from the conversion circuit arranged in an array, wherein the LED units are controlled in light emission in parallel based on bit information of corresponding parallel data to emit optical information signals dispersed in a spatially predetermined range, and of a receiving apparatus having a plurality of photo-diodes arranged in an array for emitting electric signals of levels in accordance with amounts of light received, wherein the photo-diodes output electric signals in parallel.

Abstract: A receiving apparatus and transmitting apparatus capable of transmitting and receiving a high speed optical signal and a communication system using the same, including a transmitting apparatus having a conversion circuit for converting serially input data to a plurality of bits of parallel data given predetermined information and an LED array having a number of LED units corresponding to the number of bits of the parallel data from the conversion circuit arranged in an array, wherein the LED units are controlled in light emission in parallel based on bit information of corresponding parallel data to emit optical information signals dispersed in a spatially predetermined range, and of a receiving apparatus having a plurality of photo-diodes arranged in an array for emitting electric signals of levels in accordance with amounts of light received, wherein the photo-diodes output electric signals in parallel.

Abstract: A receiving apparatus and transmitting apparatus capable of transmitting and receiving a high speed optical signal and a communication system using the same, including a transmitting apparatus having a conversion circuit for converting serially input data to a plurality of bits of parallel data given predetermined information and an LED array having a number of LED units corresponding to the number of bits of the parallel data from the conversion circuit arranged in an array, wherein the LED units are controlled in light emission in parallel based on bit information of corresponding parallel data to emit optical information signals dispersed in a spatially predetermined range, and of a receiving apparatus having a plurality of photo-diodes arranged in an array for emitting electric signals of levels in accordance with amounts of light received, wherein the photo-diodes output electric signals in parallel.

Abstract: A free-space optical communication system serves transmit/receive subscriber terminals. Each subscriber terminal includes a photo-detector and one or more sources of modulated radiation. A base terminal comprises sources of modulated optical radiation intended for the subscriber terminals and a receiving system for receiving modulated radiation from the subscriber terminals. At the base terminal, and preferably at each subscriber terminal, each source has an associated beam shaping device. The receiving system includes photo-detectors and a shared wide-angle objective implemented as a single lens. Within the base terminal, the objective lens is optically coupled only to the photo-detectors of the receiving system, and the beam shaping devices at that terminal do not have common optical elements with the lens or with each other.

Abstract: Optical space transmission device including a light source for emitting a light beam modulated according to a signal to be transmitted, an optical system for sending out the light beam emitted from the light source as a transmission light beam with an angle of expansion, a temperature detector for detecting the internal temperature of the device, and control means for changing the angle of expansion of the transmission light beam as a function of the temperature detected by the temperature detector.

Abstract: The invention relates to a method for communicating multimedia data between electronic devices by means of IR ray, which comprises the steps of converting data to be transmitted into a document by a document processing program installed in an electronic device for transmission, appending a filename extension thereto for classifying the document, transmitting the document through an IR transceiving control signal by an IR transceiver of the said electronic device, receiving the control signal as an indicative of the transmitted document by another electronic device for receiving, and identifying and processing the received document based on the filename extension thereof so as to create an identifiable data.

Abstract: A free-space optical communication apparatus includes a storage unit which stores angle-setting information for the mirror for communicating with each of the plurality of other apparatuses, a mirror driving unit which drives the mirror to an angle corresponding to the stored angle-setting information, an optical detecting unit which, on one occasion for communicating with a specified communication apparatus among the plurality of other apparatuses, detects the incident state of an optical beam sent from the specified apparatus, and a control unit which, based on the detected incident state of the optical beam, determines angle-correcting information for correcting the stored angle-setting information for the specified apparatus, and which, on the next occasion for communicating with the specified apparatus, uses the mirror driving unit to drive the mirror to an angle corresponding to the angle-setting information corrected by the angle-correcting information.

Abstract: An optoelectronic transceiver including an optoelectronic transmitting unit disposed along an optical axis and having a radiation-emitting layer region and an active radiation-sensitive layer region. The optoelectronic transceiver further including an optoelectronic receiving unit disposed along the optical axis and is disposed in bridge-like fashion above the optoelectronic transmitting unit. The optoelectronic receiving unit having an active radiation-sensitive layer region disposed perpendicular to the optical axis and located in a thin membrane, which is disposed immediately in front of the radiation-emitting layer region of the optoelectronic transmitting unit, and a radiation-emitting layer region.

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: A method that allows an optical wireless communication link between transmitting and receiving stations to be established and used reliably without the need for position sensing capabilities. A small random nudge of the center of the acquisition spiral is used to prevent a link from being established before proper alignment is attained or to correct the alignment of an established link which does not have sufficient alignment to maintain a high bandwidth link.

Abstract: In an electronic device, plural circuit boards are plugged into respective connectors, or sockets, in a common backplane circuit board. The backplane maintains the flat circuit boards in fixed relation to one another. Each circuit board is provided with a respective optical transmitter and/or receiver to allow for the transmission of (typically digital) information via a high speed carrier in a light beam through unobstructed free space between the circuit boards. The circuit boards may also be provided with optical splitters and/or combiners as well as apertures to permit light signals to pass through the board's substrate to allow for communication between plural circuit boards. The circuit boards may further include small lenses and/or opaque elements to provide an optical path having selected physical characteristics.

Abstract: A receiving apparatus and transmitting apparatus capable of transmitting and receiving a high speed optical signal and a communication system using the same, including a transmitting apparatus having a conversion circuit for converting serially input data to a plurality of bits of parallel data given predetermined information and an LED array having a number of LED units corresponding to the number of bits of the parallel data from the conversion circuit arranged in an array, wherein the LED units are controlled in light emission in parallel based on bit information of corresponding parallel data to emit optical information signals dispersed in a spatially predetermined range, and of a receiving apparatus having a plurality of photo-diodes arranged in an array for emitting electric signals of levels in accordance with amounts of light received, wherein the photo-diodes output electric signals in parallel.

Abstract: A receiving apparatus and transmitting apparatus capable of transmitting and receiving a high speed optical signal and a communication system using the same, including a transmitting apparatus having a conversion circuit for converting serially input data to a plurality of bits of parallel data given predetermined information and an LED array having a number of LED units corresponding to the number of bits of the parallel data from the conversion circuit arranged in an array, wherein the LED units are controlled in light emission in parallel based on bit information of corresponding parallel data to emit optical information signals dispersed in a spatially predetermined range, and of a receiving apparatus having a plurality of photo-diodes arranged in an array for emitting electric signals of levels in accordance with amounts of light received, wherein the photo-diodes output electric signals in parallel.

Abstract: A digital optical communication device includes an optical reception circuit converting an optical signal received from any external source to an electric signal, a decoding circuit decoding the electric signal resultant from conversion by the optical reception circuit and judging whether or not the decoding is normally completed, a reception light intensity level judgement circuit judging an intensity level of received light based on the electric signal, a coding circuit coding transmission data, and an optical transmission circuit determining a light emission intensity based on result of the judgement by the reception light intensity level judgement circuit and on result of the judgement by the decoding circuit, and converting the transmission data coded by the coding circuit to an optical signal with the light emission intensity.

Abstract: A physiological function assisting device 1 is embedded in the body, and is provided with a transmitter 11 and receiver 12 for communicating with an external controller 2. External controller 2 controls embedded physiological function assisting device 1 from the outside. External controller 2 is provided with a transmitter 21 and receiver 22 for communicating with physiological function assisting device 1. Transmitters 11,21 modulate the plane of polarization of laser light, and emit the result as a transmission signal. Receivers 12,22 selectively receive light of a specific polarization state. Receivers 12,22 respectively output electric signals corresponding to the polarization state (polarization angle or ellipticity) of the received light. As a result, full duplex communications between a strongly dispersing medium like the human body and the outside is possible, while the power consumed by the internal device can be reduced.

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: A receiving apparatus and transmitting apparatus capable of transmitting and receiving a high speed optical signal and a communication system using the same, including a transmitting apparatus having a conversion circuit for converting serially input data to a plurality of bits of parallel data given predetermined information and an LED array having a number of LED units corresponding to the number of bits of the parallel data from the conversion circuit arranged in an array, wherein the LED units are controlled in light emission in parallel based on bit information of corresponding parallel data to emit optical information signals dispersed in a spatially predetermined range, and of a receiving apparatus having a plurality of photo-diodes arranged in an array for emitting electric signals of levels in accordance with amounts of light received, wherein the photo-diodes output electric signals in parallel.

Abstract: The invention relates to a wireless keyboard capable of operating with a radiation-based signal receiver of a computing apparatus. The wireless keyboard includes a radiation-based signal transmitter functions converting a corresponding key signal into a radiation beam and emitting the radiation beam. The wireless keyboard also includes a user-adjustable guiding device having a first end and a second end. The first end abuts on the radiation-based signal transmitter such that the radiation beam emitted by the radiation-based signal transmitter enters into the guiding device from the first end. The guiding device also leads the radiation beam out from the second end. The radiation beam, led out from the second end of the guiding device, has a covered zone.

Abstract: An optical free-space communication apparatus includes a first light-emitting source for emitting a first transmission optical beam having a plane of polarization in a predetermined direction, the first transmission optical beam being modulated according to a primary signal containing communication information, a second light-emitting source for emitting a second transmission optical beam having a plane of polarization perpendicular to the plane of polarization of the first transmission optical beam, the second transmission optical beam being modulated according to an auxiliary signal for angle detection, a transmitting optical system for emitting the first and second transmission optical beams out of the apparatus as optical beams each having a predetermined angle of divergence, and a driving unit for redirecting the outgoing paths of the first and second transmission optical beams, wherein the second transmission optical beam has a larger angle of divergence than the first transmission optical beam.

Abstract: Building-to-building over the air transmission of optical data is a growing area of data communications. The fast growing use of bandwidth mandates the use of over the air transmission equipment capable of similar performance as the performance of fiber optic transmission, for distances of 3-10 Km. Transparent transmission is important to enable seamless growth from low data-rare to Gbps rates, and then to Dense Wavelength Division Multiplexed (DWDM) transmission of several wavelengths. The only way to achieve the required performance is with narrow, directable beams. This patent application discloses a Micro-Electro-Mechanical-Systems (MEMS) mirror based, over the air, optical data transmission system. A narrow optical beam is used and a MEMS mirror fine-tunes the aiming of the beam to track building movement, vibrations etc.

Abstract: A receiving apparatus and transmitting apparatus capable of transmitting and receiving a high speed optical signal and a communication system using the same, including a transmitting apparatus having a conversion circuit for converting serially input data to a plurality of bits of parallel data given predetermined information and an LED array having a number of LED units corresponding to the number of bits of the parallel data from the conversion circuit arranged in an array, wherein the LED units are controlled in light emission in parallel based on bit information of corresponding parallel data to emit optical information signals dispersed in a spatially predetermined range, and of a receiving apparatus having a plurality of photo-diodes arranged in an array for emitting electric signals of levels in accordance with amounts of light received, wherein the photo-diodes output electric signals in parallel, for selecting information in accordance with the optical information signal based on the electric signals

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: Lightwaves (1), which carry data signals and beacon light, are used for establishing a connection between a receiver and a transmitter located remote from each other. An acquisition sensor (171) is provided for acquiring the lightwaves (1) in the receiver, which generates acquisition sensor signals (Sc) from the received lightwaves. The lightwaves (1), which are conducted over a telescope (2) and a beam splitter (R4), are fed to the acquisition sensor (171) as well as to a fiber nutator scanning device (5). Besides useful signals (Sa, Sb), an additional signal (Sw, Sm?, Sm) is obtained with the aid of the scanning device (5), which is used for making the acquisition easier.

Abstract: A filtering technique for free space communication that features an improved extinction ratio by providing a filter that employs a bulk holographic transform function and a polarizing film. In this manner, a greater number of channels of communication may be provided in a unit volume while preventing unwanted cross-talk between the communication channels. To that end, the system includes a source of energy to direct energy along a path, a detector disposed in the path, and a filter. The filter has a surface upon which a polarizing film is disposed and a holographic transform function recorded throughout a volume thereon.

Abstract: Systems and techniques for aligning relative orientation of an optical transmitter and an optical receiver that are mounted to a common fixture in an optical transceiver.

Abstract: An optical communication terminal transmits data via an optical signal with a transmit mirror positioned to direct the optical signal. The optical communication terminal includes a processor configured to develop a control signal for a mirror controller to establish an optimal position of the transmit mirror. The optical communication terminal further includes a modulator coupled to the processor that modulates the optical signal in accordance with a position of the transmit mirror during transmission of the optical signal. The optimal position of the transmit mirror may be established by a scanning routine that adjusts the position of the transmit mirror to a plurality of predetermined offset positions during transmission of the optical signal. The intensity of the optical signal as received by a further optical communication terminal is then determined and provided via modulation of a further optical signal transmitted back to the first-named optical communication terminal.

Abstract: An optical free-space communication apparatus includes a first light-emitting source for emitting a first transmission optical beam having a plane of polarization in a predetermined direction, the first transmission optical beam being modulated according to a primary signal containing communication information, a second light-emitting source for emitting a second transmission optical beam having a plane of polarization perpendicular to the plane of polarization of the first transmission optical beam, the second transmission optical beam being modulated according to an auxiliary signal for angle detection, a transmitting optical system for emitting the first and second transmission optical beams out of the apparatus as optical beams each having a predetermined angle of divergence, and a driving unit for redirecting the outgoing paths of the first and second transmission optical beams, wherein the second transmission optical beam has a larger angle of divergence than the first transmission optical beam.