Abstract: A method and system for optical communication with between a device and a remote station include passing light incoming from the remote station and outgoing to the remote station through a lens system and an aperture of the device, for example the lens system comprising a Plössl lens or a double-Gauss lens. The method and device include receiving the incoming light at an optoelectronic assembly that has an array of VCSELs, an array of microlenses, and a plurality of photodetectors configured to generate an output signal in response to detected light. The VCSELs may be arranged in clusters for simultaneous emission, and multiple clusters may also be activated for simultaneous emission.

Abstract: An optical system for responding to distortions in incident light in a free space optical communication system includes a machine learning output storing at least an indication of multiple images and corresponding positioning or orientation attributes for one or more optical elements; a sensor configured to generate an image; and a component configured to adjust the one or more optical elements based on the generated image. Various other methods, systems, and apparatuses are also disclosed.

Abstract: A system includes: a light source; a detector configured to spectrally resolve light across an operative wavelength range; a retroreflector module including a reflector and an optical filter integrated with the reflector, the reflector being configured to retroreflect at least some of incident light across the operative wavelength range; an optical filter configured to filter light across the operative wavelength range, the optical filter having an angular-dependent optical characteristic for light across the operative wavelength range; and an electronic processing module in communication with the detector.

Abstract: An injection locked transmitter for an optical communication network includes a master seed laser source input substantially confined to a single longitudinal mode, an input data stream, and a laser injected modulator including at least one slave laser having a resonator frequency that is injection locked to a frequency of the single longitudinal mode of the master seed laser source. The laser injected modulator is configured to receive the master seed laser source input and the input data stream, and output a laser modulated data stream.

Abstract: An optical communication apparatus includes an optical signal transmitting unit to output an optical signal; an optical signal receiving unit to receive an optical signal; a retro-reflector to retro-reflect the received optical signal in a direction opposite to an incident angle of the received optical signal; and a control unit to direct the retro-reflector to receive the optical signal and to retro-reflect a response signal, which includes the received optical signal and data to be transmitted, in response to the received optical signal.

Abstract: Example method, apparatus, and system embodiments are disclosed to provide a high data throughput optical communication link. An example embodiment comprises: a high frequency optical receiver configured to receive signals modulated with high frequency data; an optical waveguide having a receiving portion and a transmitting portion juxtaposed with the receiver, configured to transfer signals incident on the receiving portion, to the transmitting portion, and to transmit the signals to the receiver; a guide portion configured to releasably engage another apparatus, for positioning the waveguide with respect to the other apparatus, to receive at the receiving portion of the waveguide, signals from the other apparatus, for delivery to the receiver; and a wireless power circuit configured to exchange wireless power with the other apparatus, to convert between electrical signals modulated with high frequency data and the optical signals modulated with high frequency data received by the waveguide.

Abstract: A satellite test signal reflection apparatus for testing transmitters sending out optical signals, the apparatus includes a plate that is at least partially permeable to optical signals. The plate has a base with a first surface with a residual reflective coating and a second surface. The residual reflective coating is configured to split an optical beam, which penetrates the plate in a first direction from the first surface to the second surface, into a reflective optical beam and a transmitted optical beam.

Abstract: A wavelength sensing lighting system may include a light source, a sensor and a controller. One or more light sources and sensors may be included in an array. The light source may emit an illuminating light and the sensor may sense an environmental light. The illuminating light may include data light. The lighting system may include a plurality of nodes connected in a network. The nodes may communicate by emitting and receiving the data light, which may be analyzed by the controller. The light source and the sensor may be provided by a light emitting semiconductor device that is capable of emitting illuminating light and receiving environmental light. A conversion material may convert the wavelength of a source light into a converted light. The conversion material may increase the wavelength range of light emittable and detectable by the lighting system.

Abstract: According to one embodiment, there is provided a visible-light communications system in which bidirectional visible-light communication is performed between a visible-light communications device and a mobile terminal. The device has one light source. The mobile terminal has a retroflection unit. The mobile terminal further has first and second optical filters. The first optical filter extracts a visible light beam modulated with the data transmitted from the visible-light communications device. The second optical filter extracts a visible light beam that will be used as a retroflection light beam that is not modulated.

Abstract: An apparatus includes an N×1 spatial mode multiplexer, an optical source and an optical receiver. The spatial mode multiplexer has N input ports and an output port end-couplable to a multimode optical fiber. The multiplexer is configured to preferentially couple light between individual ones of the input ports and corresponding spatial optical modes of the multimode optical fiber. The optical source is connected to a first one of the input ports to launch an optical probe pulse into the fiber. The optical receiver is connected to electrically analyze an optical signal backscattered from the multimode optical fiber and output by a second one of the input ports in response to the launch of the optical probe pulse into the fiber.

Abstract: The present invention relates generally to optical rotary joints (35) for enabling optical communication between a rotor and a stator, and to improved optical reflector assemblies for use in such optical rotary joints.

Abstract: The invention relates to a method of operating an optical transmission system (100a, 100b, 100c), wherein at least one optical data signal is transmitted over an optical transmission link (120), which particularly comprises at least one optical fiber (120a). The inventive method is characterized by modulating (200) said data signal with a test signal (s) having a predetermined modulation frequency fmod to obtain a modulated data signal (Pin), by receiving (210) a reflected portion (Pback) of said modulated data signal (Pin), and by determining (220) a fiber quality measure (a) depending on said received reflected portion (Pback) of said modulated signal (Pin).

Abstract: An optical modulation system includes a metamaterial structure configured to receive and process an input optical signal at at least one operational wavelength, where the metamaterial structure changes between a transmissive state and a non-transmissive state with respect to the optical signal(s) at the operational wavelength(s) in response to an external stimulus applied to the metamaterial structure. An external stimulus source is coupled with the metamaterial structure and is configured to change the metamaterial structure between its transmissive and non-transmissive states by applying selected stimulus pulses to the metamaterial structure. The optical modulation system processes the input optical signal to output a modulated optical signal that modulates in correspondence with the selected pulses applied to the metamaterial structure.

Abstract: Reduced Rayleigh backscattering effect enables a longer-reach optical access communication network-thus it eliminates significant costs. Furthermore, a wavelength to an intelligent subscriber subsystem can be dynamically varied for bandwidth on-Demand and service on-Demand. A software module renders intelligence (and context awareness) to a subscriber subsystem and an appliance. An object can sense/measure/collect/aggregate/compare/map and connect/couple/interact (via one or more or all electrical/optical/radio/electro-magnetic/sensor/bio-sensor communication network(s) within and/or to and/or from an object) with another object, an intelligent subscriber subsystem and an intelligent appliance utilizing an Internet protocol version 6 (IPv6) and its subsequent versions. A construction of a near-field communication (NFC) enabled intelligent micro-subsystem and/or intelligent appliance with key applications (e.g.

Abstract: A wavelength sensing lighting system may include a light source, a sensor and a controller. One or more light sources and sensors may be included in an array. The light source may emit an illuminating light and the sensor may sense an environmental light. The illuminating light may include data light. The lighting system may include a plurality of nodes connected in a network. The nodes may communicate by emitting and receiving the data light, which may be analyzed by the controller. The light source and the sensor may be provided by a light emitting semiconductor device that is capable of emitting illuminating light and receiving environmental light. A conversion material may convert the wavelength of a source light into a converted light. The conversion material may increase the wavelength range of light emittable and detectable by the lighting system.

Abstract: A system for monitoring a plurality of components distributed in different space locations, includes: at least one optical fiber path; an optical radiation source adapted to inject optical radiation into the at least one optical fiber path; at least one first and at least one second optical branches branching from the at least one optical fiber path and adapted to spill respective portions of the optical radiation, the first and second optical branches being adapted to be operatively associated with a respective component to be monitored.

Abstract: Methods and apparatus for target identification are disclosed. An example method for target identification disclosed herein comprises establishing an optical communication link with a potential target, transmitting a first signal encoded with a first code to the potential target using the optical communication link, receiving a second signal from the potential target using the optical communication link, extracting a second code from the second signal, and identifying the potential target as a friendly asset based on the second code.

Abstract: A retro-reflective identification tag capable of modulating an optical signal whereby to support bi-directional communication with an associated remote optical interrogation device. The tag comprises a MOEMS modulating layer over a retro-reflective substrate, giving the tag a wide angle of effective operation. The tag modulator may optionally be switched on only responsive to detection of a precursor beam from the interrogation system in order to save power. The interrogation device may make use of multiple optical wavelengths for communicating with the tag.

Abstract: Methods, systems and other embodiments associated with a laser communication system using a single wavelength are presented. A first data is modulated onto an RF carrier to produce a modulated RF carrier. A laser is intensity modulated using with the modulated RF carrier. The intensity modulated laser beam is transmitted from an interrogator to a modulating retro-reflector (MRR) terminal. A portion of the laser beam is received at a receiver at the MRR terminal. Another portion of the laser is modulated at the MRR terminal with a second data to produce a re-modulated laser beam. The re-modulated laser beam is reflected back to the interrogator.

Abstract: A retroreflector coupled with a polarization rotator is provided according to some embodiments. The polarization rotator can be designed and/or configured to introduce a fraction of a wavelength phase difference in a received beam of light prior to reflecting the beam of light back toward the source of the light. By switching the state of the polarization rotator a communication signal can be modulated on the return beam of light.

Abstract: An optical transmission system using Raman optical amplification, which is configured in a WDM-PON topology where a signal light between an optical line terminal and each of optical network units is multi/demultiplexed at a WDM. The optical line terminal supplies continuous lights having wavelengths to the optical network units through an optical fiber from the optical line terminal. The continuous lights are used for an uplink signal. In addition, the optical line terminal outputs a pumping light having a wavelength which is used to excite lights of the continuous lights, to the optical fiber from the optical line terminal.

Abstract: An optical system for remotely optical communications at a high data rate between a base station and a remote station under atmospheric turbulence conditions is disclosed. The remote station includes an entirely different type of retroreflector that does not use the conventional type of retroreflection, but instead consists of two sets of lenslets coupled with single-mode fiber array, called fiber “retro”. Amplified retromodulation is achieved requiring only one single optical amplifier and one single modulator. A transmitter located at the base station sends an interrogating optical beam to the fiber “retro” which modulates the optical beam according to the input signal/data, and redirects the modulated optical beam to the base station for detection by a receiver. The present invention includes the capabilities of providing Identification of Friend-or-Foe (IFF), secure communication, and a means of achieving a wide field-of-view (FOV) with a fiber-coupled lenselet array.

Abstract: An apparatus for retro-reflecting electromagnetic energy and a method for producing the same are provided. The apparatus includes a substrate and a plurality of corner mirrors disposed in said substrate. The plurality of corner mirrors may have respective angles of acceptance with respect to the substrate to be operable to retro-reflect the electromagnetic energy within the respective angles of acceptance. The plurality of corner mirrors are arranged to provide a combined angle of acceptance that is greater than any one of the respective angles of acceptance. The apparatus may also include at least one modulator disposed over at least a portion of said plurality of corner mirrors. The modulator is operable to modulate any of said electromagnetic energy received and retro-reflected.

Abstract: A system, method, and communication device are disclosed. The system can include an optical interrogator and a phase-modulating communication device. The communication device can include a retro-optimized lens, a phase modulator, and a processor. The retro-optimized lens can be a non-imaging optical arrangement configured to minimize deviation between an incoming signal and a reflected signal used for return link communications. The processor can be configured to calibrate a modulation path length of the communication device based on a wavelength of the communication signal and can control an operation of the phase-modulator to send phase-coded messages to the interrogator. Optionally, the processor can perform a real-time phase calibration of the communication device using feedback from the interrogator.

Abstract: A computer including: a casing, at least a portion of which contains a potting material acting as an optical waveguide material; a transmitter for transmitting a pulse based signal at least partially through the potting material acting as the optical waveguide material; and a receiver for receiving the pulse based signal after one or more reflections of the pulse based signal from interior surfaces of the casing; the pulse based signal having a pulse rate configured such that a subsequent pulse doesn't interfere with reflections from an immediately previous pulse.

Abstract: Disclosed herein is a visible-light communication system according to one embodiment of the invention. The system comprises two apparatus. One apparatus emits a visible light beam on which is superimposed transmission data. From the void data represented by the visible light beam, the other apparatus generates a retroflected light beam, superimposes transmission data on the retroflected light beam, and applies the retroflected light beam to the apparatus. On receiving the retroflected light beam, the apparatus identifies the transmission data coming from the other apparatus, on the basis of the identification data superimposed on the retroflected light beam.

Abstract: An optical interconnect includes a reflective body having a plurality of faces, where the body is translatable in a plane; and an optical receiver configured to receive optical energy reflected by at least one of the faces.

Abstract: A processor can determine a relative position within a room of a person wearing a force-on-force device based exclusively upon sensed optical signals detected by optical sensors connected to the force-on-force device. Each of the sensed optical signals is geographically focused within a spatially constrained zone. Each sensed optical signal can further include digitally encoded data indicating an optical source that emitted the sensed optical signal and a spatially constrained zone of the sensed optical signal. The relative position can be determined based on determining a grid within the room within which the person is located. The grid can be defined by overlapping ones of the spatially constrained zones of the sensed optical signals.

Abstract: Methods of providing duplex free-space optical, communication comprising receiving a time-shift keying (TSK) encoded signal and selectively re-modulating—and optionally retro-reflecting —received TSK pulses so as to transmit an on-off keying (OOK) signal wherein modulation is achieved by operating a micro-opto-electronic mechanical system (MOEMS) device having a oscillation period, the difference in timing between logic 1 and logic 0 pulses of the TSK encoded signal being such that each pulse arrives at a time within a single MOEMS device oscillation period chosen to ensure high or low transmissivity through the MOEMS device independent of incident TSK encoded signal pulse value (0 or 1).

Abstract: A device for optical remote monitoring, preferably an optically readable membrane-based microphone, and a system including such a device is provided. The device for optical remote monitoring includes a retroreflector and an acoustic membrane. The acoustic membrane suitably is a light-modulating component and modulates the reflection of an incident light beam in relation to the pressure field, from a sound source, to which the membrane is exposed. The retroreflector may be a corner cube having three sides with the membrane arranged on one of the sides. The membrane can be part of a side or one side may consist of a membrane.

Abstract: A drive circuit and method of controlling a quantum well modulator are disclosed. The drive circuit can be disposed in an optical transceiver having a quantum well modulator configured to retro-modulate an incoming optical signal. The drive circuit can include separate modulating and bias voltage sources. A level of the modulating voltage and the bias voltage can be determined based on an ambient temperature of the optical transceiver and can be adjusted to compensate for variations in the optical performance of the quantum well modulator. The quantum well modulator can be controlled in intervals. The modulating voltage can be applied to the quantum well modulator during a first interval. A current associated with the modulating voltage can be returned to the modulation voltage source during a second interval. A timing of the first and second intervals can be based on electrical properties of the quantum well modulator.

Abstract: Data is transmitted between a central office and customer premises by a wavelength division multiplex passive optical network. Two laser beams with separate wavelengths are transmitted from the central office to an optical network unit in the customer premises. Both laser beams carry downstream data. One laser beam is intensity modulated by on/off keying. The other laser beam is phase modulated by differential phase shift keying, which maintains a constant optical intensity. The first laser beam is received by a first optical receiver, which demodulates the first downstream data. The second laser beam is split in two. One laser beam is sent to a second optical receiver, which demodulates the second downstream data. The other laser beam is sent to a reflective semiconductor amplifier, which modulates the beam with upstream data and transmits the beam back to a receiver in the central optical system.

Abstract: A marker-tracking system includes an object, a marker illuminating device, a marker sensing device, and a computing device. The object includes a first retroreflective marker having a shape that is substantially defined by two spherical caps of different radii that are disposed substantially concentric in relation to one another. The marker illuminating device substantially illuminates the first retroreflective marker, the marker sensing device detects the illuminated first retroreflective marker and generates first data indicative of the location of the illuminated first retroreflective marker in space, and the computing device processes the first data generated by the marker sensing device to determine a position and/or orientation of the object in space.

Abstract: A communication system, the communication system includes: a first decision entity; and a long laser that includes a first reflector and a second reflector; wherein a lasing characteristic of the long laser is responsive to: (i) first data unit that is provided by a first user and affects a reflection spectrum of the first reflector, and (ii) second data unit that is provided by a second user and affects a reflection spectrum of the second reflector; and wherein the first decision entity is adapted to receive the first data unit and information representative of the lasing characteristic, as well as to determine (i) a relationship between the first data unit and the second data unit, or (ii) a content of the second data unit.

Abstract: A portable wireless terminal for performing visible light communication with other devices through free space includes an optical detector for generating an electrical signal after photoelectrically converting some of optical signal input from free space and outputting the electrical signal; a reflector for retro-reflecting the others of the optical signal incident on the concave grooves, the reflector having a reflection surface on which at least one concave groove is formed; and a modulator for outputting the retro-reflected optical signal after data modulation.

Abstract: An alternative design is given for an optimized quantum cryptographic entangling probe for attacking the BB84 protocol of quantum key distribution. The initial state of the probe has a simpler analytical dependence on the set error rate to be induced by the probe than in the earlier design. The new device yields maximum information to the probe for a full range of induced error rates. As in the earlier design, the probe contains a single CNOT gate which produces the optimum entanglement between the BB84 signal states and the correlated probe states.

Abstract: A method for point-to-point communication over an optical channel is provided. An optical beam is received at a first corner cube modulated retro-reflector. Simultaneously, the optical beam is received at a second corner cube modulated retro-reflector. The first and second corner cube modulated retro-reflectors are adjacent to each other, are co-boresighted, and have an aggregate diameter that is smaller than the far-field Instantaneous Field of View of a receiver. The optical beam is modified by the first corner cube modulated retro-reflector by adding a first modulation to the optical beam, forming a first modulated optical beam. Simultaneously, the optical beam is modified by the second corner cube modulated retro-reflector by adding a second modulation to the optical beam, forming a second modulated optical beam. The first modulated optical beam and the second modulated optical beam combine to form a modified optical wavefront, which is reflected to a sender.

Abstract: A combat IFF system, for use in a combat exercise or on the battlefield, including a helmet-mounted passive IFF response unit and a weapon-mounted IFF interrogatory unit for each soldier. Infrared (IR) signals are employed for both challenge and response. The IR response signal is a very narrowly-targeted reflection of the relatively narrow IR transmit signal, thereby minimizing interception opportunities. The transmit and response signals are encoded in a transaction that cannot be compromised even when either or both signals are intercepted and decoded by the enemy. The combat IFF system includes biometric anti-spoofing features that prevent any use by an enemy in possession of captured units. Military radio-frequency (RF) spectrum is not required so there are no bandwidth limitations on simultaneous IFF transactions in the battlefield. A combat IFF transaction is completed in milliseconds.

Abstract: A secure optical communication scheme uses differential delay D in an unbalanced Mach-Zehender interferometer to provide two copies of the optical source signal at a remote phase modulator separated in time by D. As D is much bigger than the coherence time source, the two copies of the signal are effectively uncorrelated. Both signals are phase-modulated by the remote sender's data and returned to the unbalanced interferometer. The phase modulator will be converted into amplitude modulation by the action of the interferometer.

Abstract: Systems and methods for encoding information in the topology of superpositions of helical modes of light, and retrieving information from each of the superposed modes individually or in parallel. These methods can be applied to beams of light that already carry information through other channels, such as amplitude modulation or wavelength dispersive multiplexing, enabling such beams to be multiplexed and subsequently demultiplexed. The systems and methods of the present invention increase the number of data channels carried by a factor of the number of superposed helical modes.

Abstract: A system, method, and communication device are disclosed. The system can include an optical interrogator and a phase-modulating communication device. The communication device can include a retro-optimized lens, a phase modulator, and a processor. The retro-optimized lens can be a non-imaging optical arrangement configured to minimize deviation between an incoming signal and a reflected signal used for return link communications. The processor can be configured to calibrate a modulation path length of the communication device based on a wavelength of the communication signal and can control an operation of the phase-modulator to send phase-coded messages to the interrogator. Optionally, the processor can perform a real-time phase calibration of the communication device using feedback from the interrogator.

Abstract: The present invention is directed toward systems for conducting laser range and enabling optical communication between a plurality of entities and to the application of such systems in a secure covert combat identification system. In one embodiment, the present invention uses a novel laser system that generates high pulse rates, as required for optical communications, while concurrently generating sufficiently high power levels, as required by laser range finding operations. One application of the present invention is in enabling secure covert communications between a plurality of parties. Another application of the present invention is in tracking and identifying the movement of objects.

Abstract: A system and method for encoding an analog input signal for optical transmission, including driving a voltage controlled oscillator with an analog input signal to produce a frequency modulated electrical signal having a frequency proportional to the amplitude of the input signal, and applying the frequency modulated electrical signal to a multiple quantum well modulating retroreflector. The retroreflector receives optical energy from a laser source and modulates the optical energy with the frequency modulated signal to produce an output optical signal.

Abstract: System and techniques for transmitting information from a remote information source use a reflector for reflecting a laser beam or other light source back to its originating location. A reflector coupled to an information source receives a laser beam from a laser source. A movement of at least one surface of the reflector is controlled to modulate the laser beam, and the modulated laser beam is reflected toward the laser source. The modulated laser beam can be received by a receiver at or near the laser source to detect and decode data embedded in the modulated laser beam.

Abstract: In order to facilitate alignment of a QKD transmitter and QKD receiver, the transmitter is provided with a retro-reflector for returning to the receiver a photon beam originating at the latter. The transmitter is arranged to polarization modulate the retro-reflected beam. The transmitter is provided both with an intensity detector for generating an indication of retro-reflected photon intensity, and an intensity-dependent controller for controlling the QKD transmitter in dependence on the detected photon intensity. In one embodiment, this control involves aborting operation of the QKD transmitter upon an unexpectedly high photon intensity being detected; in another embodiment, the intensity indication is used to control the attenuation of the retro-reflected beam so as stabilize the average retro-reflected photon count per unit time.

Abstract: An optical communication apparatus includes an optical signal transmitting unit to output an optical signal; an optical signal receiving unit to receive an optical signal; a retro-reflector to retro-reflect the received optical signal in a direction opposite to an incident angle of the received optical signal; and a control unit to direct the retro-reflector to receive the optical signal and to retro-reflect a response signal, which includes the received optical signal and data to be transmitted, in response to the received optical signal.

Abstract: An optical transmission apparatus is provided in which high optical output power is secured in an optical transmitter, the fine adjustment of the optical axis is unnecessary, and the propagation range of the optical output signal can be adaptively changed. A diffusing liquid lens includes a first liquid and a second liquid containing a scattering material that scatters light, and the curvature of the boundary surface between the first and the second liquids is changed according to the control voltage applied from a controlling unit. A first optical signal outputted from a light emitting device is diffused in the first liquid, and emitted as a second optical signal having a spread angle corresponding to the curvature of the boundary surface and a substantially uniform radiant intensity distribution.

Abstract: The present invention pertains to radiant energy systems and more particularly to systems exhibiting the retroreflection principle wherein the system comprises a focusing means and a surface exhibiting some degree of reflectivity positioned near the focal plane of the device, and wherein incident radiation falling within the field-of-view of said system is reflected back in a direction which is parallel to the incident radiation. The present invention has great applicability in military optical system applications for detecting the presence of an enemy employing surveillance equipment and for neutralizing this surveillance capability.

Abstract: The present invention pertains to radiant energy systems and more particularly to systems exhibiting the retroreflection principle wherein the system comprises a focusing means and a surface exhibiting some degree of reflectivity positioned near the focal plane of the device, and wherein incident radiation falling within the field-of-view of said system is reflected back in a direction which is parallel to the incident radiation. The present invention has great applicability in military optical system applications for detecting the presence of an enemy employing surveillance equipment and for neutralizing this surveillance capability.

Abstract: The present invention pertains to radiant energy systems and more particularly to systems exhibiting the retroreflection principle wherein the system comprises a focusing means and a surface exhibiting some degree of reflectivity positioned near the focal plane of the device, and wherein incident radiation falling within the field-of-view of said system is reflected back in a direction which is parallel to the incident radiation. The present invention has great applicability in military optical system applications for detecting the presence of an enemy employing surveillance equipment and for neutralizing this surveillance capability.