A laser device for optical communication comprises a first laser unit connected to a first optical fiber for supplying a transmission laser beam thereto. wherein the laser device is configured for providing a reference laser beam in addition to the transmission laser beam. For providing the reference laser beam the laser device further includes a second laser unit connected to a second optical fiber for supplying the reference laser beam to the second optical fiber. The first laser unit is configured for providing the transmission laser beam as a linear polarized beam that is polarized in a first polarization direction, and the second laser unit is configured for providing the reference laser beam as a linear polarized beam that is polarized in a second polarization direction. The first optical fiber and the second optical fiber are formed of polarization maintaining optical fibers, and the laser device further includes a polarization combiner connected to a third polarization maintaining optical fiber for conveying the transmission laser beam and the reference laser beam to an optical output of the laser device.

An apparatus includes polarization beamsplitters that each separate incoming and outgoing optical signals having different polarizations. The apparatus also includes directionally-dependent polarization rotation optical assemblies that each maintain a polarization of one of the incoming and outgoing optical signals and to rotate a polarization of another of the incoming and outgoing optical signals. The apparatus further includes a third polarization beamsplitter that combines the outgoing optical signals to produce transmit optical signals and separate receive optical signals to produce the incoming optical signals.

A free space optical (FSO) communication node communicates via an FSO link with a remote FSO communication node that moves relative to the FSO node. The FSO node may be highly directional, and transmit (Tx) and receive (Rx) beams of the FSO node may share optical paths (at least in part). Instead of directing a Tx beam along a point ahead angle relative to a Rx beam (which may result in undesirable Rx coupling losses), the Tx beam is directed based on the point ahead angle and a point ahead offset angle. The point ahead offset angle modifies the point ahead angle to reduce Rx coupling losses while keeping Tx pointing losses at least low enough to maintain the FSO link. In some cases, due to the point ahead offset angle, the Tx direction minimizes a sum of the Rx coupling losses and the Tx pointing losses.

A system includes a high energy laser (HEL) configured to transmit a HEL beam and a beacon illumination laser (BIL) configured to transmit a BIL beam. The system also includes at least one fast steering mirror (FSM) configured to steer the BIL beam to be offset from the HEL beam. The system further includes at least one Coudé path FSM configured to correct for atmospheric jitter of the HEL beam and the BIL beam while maintaining the offset of the BIL beam from the HEL beam.

An optical antenna may permit a duplex link formed by a transmit, Tx, beam towards a partner optical antenna and a receive, Rx, beam from the partner antenna. The antenna includes: a proximal path including a bidirectional waveguide for duplex propagation of the duplex link from a Tx source of the Tx beam and towards a receiver of the Rx beam; a distal path for a duplex propagation of the duplex link from/towards the partner optical antenna; a beam shaper positioned in the distal path to shape a duplex propagation pattern of the duplex link; and a controller controlling the beam shaper to adaptively shape the propagation pattern to enclose: a first position of the partner antenna at the transmission of the Rx beam; and a second of the partner antenna at the reception of the Tx beam.

A pointing unit (100) for use with a free space optical (FSO) communications terminal (105) that includes an optical arrangement (101) of one or more optically transmissive steering elements (101a, 101b). The steering elements (101a, 101b) are arranged in an optical path of an incident beam (107) entering the optical arrangement (100), and the orientation of at least one element (101a, 101b), and the refractive index of at least one element (101a, 101b), are controllable to steer a beam (107b) towards a target (110).

An optical wireless communication system (1) for wirelessly transmitting a signal beam (L) between optical communication units (2) and (3) located at two points apart from each other includes an aiming mechanism (4) that is provided in each of the optical communication units (2) and (3) located at the two points and has an aiming line (S), which is parallel to an optical axis (O) and has a predetermined interval from the optical axis (O), with the optical axis (O) of the signal beam (L) of each of the optical communication units (2) and (3) located at the two points aligned in a straight line, and a first front sight that is provided in each of the optical communication units (2) and (3) and provided at a position that is off the optical axis (O) and the aiming line (S) and has a predetermined interval from the optical axis (O) and a predetermined interval from the aiming line (S).

A system with which any abnormality can easily be found is provided. A system includes: a first modulator that generates a control signal and modulates an input signal in accordance with the generated control signal, to control luminance of a first light source that emits light according to the modulated input signal, the first modulator outputting the control signal; and a second modulator that acquires a control signal output from the first modulator and modulates an input signal in accordance with the control signal, to control luminance of a second light source that emits light according to the modulated input signal. The first modulator generates, as an extinguishing signal, the control signal for extinguishing the first light source by an extinguishing period. After a lapse of the extinguishing period, the first modulator generates, as a light ID signal, the control signal for transmitting a visible light signal by luminance variations of the first light source.

A system with which any abnormality can be easily found is provided. A system includes: a first modulator that generates a control signal and modulates an input signal in accordance with the generated control signal, to control luminance of a first light source that emits light according to the modulated input signal, the first modulator outputting the control signal; a second modulator that acquires the control signal output from the first modulator and modulates an input signal in accordance with the control signal, to control luminance of a second light source that emits light according to the modulated input signal, the second modulator outputting the control signal. The first modulator generates, as a light ID signal, a control signal for transmitting a visible light signal by luminance variations of the first light source, and acquires a light information signal being the control signal output from the second modulator.

Embodiments relate to a local free space optical (FSO) terminal that transmits and receives optical beams. The FSO terminal includes a fore optic and a dispersive optical component. A receive (Rx) optical beam from a remote FSO terminal is received and focused by the fore optic to a Rx spot at a focal plane of the fore optic. A transmit (Tx) optical beam with a different wavelength forms a Tx spot at the focal plane and is collimated and projected by the fore optic to the remote FSO terminal. The dispersive optical component is positioned along optical paths of both the Rx beam and the Tx beam. Among other advantages, a wavelength dependence of the dispersive optical component laterally separates the Rx spot and the Tx spot at the focal plane.