An apparatus includes: an optical phased array (e.g., on a photonic integrated circuit), a focusing element, which can be at a fixed position relative to the optical phased array and configured to receive an optical beam from the optical phased array, and a steering element, which can be at a fixed position relative to the focusing element and configured to transmit the optical beam received from the focusing element. In some implementations, at least one of the focusing element or the steering element is externally coupled to the photonic integrated circuit.

A method, system, and apparatus are disclosed for a free-space communication optical terminal comprising an optical telescope (or telescopes) for bidirectional communication and navigation, a pointing and tracking system for transmission and reception of narrow optical beams, and a modem.

Light is modulated at a source to encode data. An additional tracking signal is imposed on the light using polarization modulation (PM). PM modulates one or more values of polarization rotation or polarization ellipticity of the light. These values may be dithered within constraints to provide a specified modulation index at the optical receiver, without impairing the encoded data. At the optical receiver, a polarization analyzer is used to recover the tracking signal, converting the polarization modulation to amplitude modulation. For example, after the light passes through the analyzer, an array of optical photodetectors detects the changes in apparent intensity resulting in the interaction between the light and the analyzer that correspond to the tracking signal. Due to a high modulation index, the recovered signal exhibits a high signal to noise ratio (SNR). The high SNR improves a noise equivalent angle, improving tracking performance.

A free space optical communications transmitter terminal including an optical source arranged to provide a first beam of light encoding information to be communicated; an optical source arranged to provide photons encoding bits of a key of a Quantum Key Distribution protocol; and an optics arrangement. The first beam and the photons are linearly polarised. The optics arrangement is configured to combine the first beam and the photons into a single, second, beam to be transmitted to a receiver terminal; and transform the linear polarisation of the first beam into one of left and right circular polarisation and transform the linear polarisation of the photons into the other of left and right circular polarisation. A receiver terminal receives the second beam, transforms the circular polarisations into orthogonal linear polarisations, and filters out the linear polarisation of the first beam to allow the photons to pass to a single photon detector.

Low power and/or low footprint optical communication technologies that support short to medium range exoatmospheric communications and provide bidirectional communication with nearly spherical coverage.

An optical space communications transmission and reception terminal includes: an optical transceiver to convert transmission data into a transmission optical signal modulated at a symbol rate synchronized with a transmission clock signal and output it, and generate received data from a reception optical signal; an intensity modulation unit to generate an intensity-modulated transmission optical signal; a transmission clock source to supply a transmission clock signal; a fiber coupling unit) to output the intensity-modulated transmission optical signal as collimated light and couple the input optical signal to an optical fiber; an optical fiber amplifier to amplify the optical signal coupled to the optical fiber; a tracking mirror to output the optical signal to the fiber coupling unit and output the transmission optical signal to space; and an angle sensor to output a clock signal extracted from the optical signal divided by a beam splitter to the optical transceiver.

A terminal is configured to communicate with another terminal using an optical link. The terminal includes an optical transmitter configured to emit an optical beam, an optical receiver configured to receive an optical signal, and a computing device configured to control the optical transmitter and to receive the optical signal from the optical receiver. The computing device is configured to establish the optical link with the another terminal by, (1) dividing an area of uncertainty, where the another terminal is located, into one spherical region (.sub.1) and an annulus ring (.sub.2)−(.sub.1), wherein each of (.sub.1) and (.sub.2) are spherical regions with radii

Various embodiments are disclosed herein with generally relate to an optical communication system using a photonic lantern. In at least one embodiment, the optical system comprises: an optical transmitter coupled to a signal transmitting path; an optical receiver coupled to a signal receiving path; a photonic lantern, the photonic lantern extending between a first open end and a second open end, the first end comprising an opening to a single multi-mode fiber, and the second end comprising a plurality of single mode fibers that are adiabatically coupled to the multi-mode fiber, the plurality of single-mode fibers includes a single-mode fiber adapted to carry a fundamental optical mode and the remaining single-mode fibers adapted to carry higher-order optical modes, wherein, the single-mode fiber is coupled to the optical transmitting path, the remaining single-mode fibers are coupled to the optical receiving path.

A method and apparatus for propagating optical Beamy light and Combi signals via a cascaded line of support devices for electrically powered wiring devices and low voltage IoTs and Ai devices, combined into homes and high—rise units for operating, control ling and reporting home automation via optical, electrical and wireless communication with no collision, by providing traffic control for signals propagation. The cascaded devices linked via plastic optical fiber or other optical cable are aided by a series of testers during installation and beyond, with the electrical and low voltage devices are installed by a plug-in action into the cascaded devices and removed by a pull hand tool.

An optronic system (100) for a countermeasure unit (10) to optically communicate with another communication terminal is disclosed. The countermeasure unit (10) comprises a laser beam source (12) and a directing device (14) for a laser beam (15) of the laser beam source (12) and is configured to dazzle or to jam an object of threat (50). The optronic system (100) comprising: a detector (110), a modulation unit (120), and a control unit (130). The detector (110) is configured to detect an incoming communication in an incoming signal (25). The modulation unit (120) is configured to demodulate the incoming signal (25) or cause a modulation of an outgoing laser beam (15). The control unit (130) is configured, in response to the detected incoming communication, to control the modulation unit (120) to demodulate the incoming signal (25) or to modulate the outgoing laser beam (15) to enable an optical communication via the laser beam source (12) of the countermeasure unit (10).