Disclosed herein are methods, devices, and system for beam forming and beam steering within ultra-wideband, wireless optical communication devices and systems. According to one embodiment, a free space optical (FSO) communication apparatus is disclosed. The FSO communication apparatus includes an array of optical sources wherein each optical source of the array of optical sources is individually controllable and each optical source configured to have a transient response time of less than 500 picoseconds (ps).

During operation, the system receives an optical input signal, and also receives a reference optical frequency comb (OFC) signal. Next, the system uses a gapless spectral demultiplexer to spectrally slice the optical input signal to produce a set of spectral slices. The system also uses a high-contrast demultiplexer to strongly isolate each combline of the reference OFC signal to produce a set of reference comblines. Next, in a parallel manner, the system demodulates each spectral slice in the set of spectral slices centered on a single reference combline in the set of reference comblines to produce a set of baseband I/Q signals, wherein each spectral slice is demodulated based on a known code sequence. The system then digitizes the set of baseband I/Q signals to produce a set of digitized signals. Finally, the system processes the set of digitized signals to directly reconstruct a waveform for the optical input signal.

In some examples, an optical time-domain reflectometer (OTDR)-based high reflective event measurement system may include an OTDR, and an N by M optical switch optically connected to the OTDR or disposed within the OTDR. The optical switch may include a variable attenuator mode and at least one optical fiber connected to at least one output port of the optical switch. At least one fiber optic reflector may be disposed at an end of the at least one optical fiber. A variable optical attenuator may reduce, for the at least one optical fiber including the at least one fiber optic reflector, an amplitude of reflective peaks.

A method for determining an optical signal power change, wherein the method includes: A first optical signal that includes a plurality of wavelength signals is obtained, where the plurality of wavelength signals are distributed in a plurality of bands. Then, an optical power of each band and a center wavelength signal of each band are detected, and a preset single-wavelength transmit power and a preset coefficient are obtained. Next, an equivalent quantity N of equivalent wavelength signals is determined, and an equivalent wavelength signal corresponding to the first optical signal is determined. Further, a target power that is used to compensate for a first power change value of the first optical signal in transmission over an optical fiber is determined based on the preset coefficient, the equivalent wavelength signal, the equivalent quantity, and the preset single-wavelength transmit power.

Consistent with an aspect of the present disclosure, electrical signals or digital subcarriers are generated in a DSP based on independent input data streams. Drive signals are generated based on the digital subcarriers, and such drive signals are applied to an optical modulator, including, for example, a Mach-Zehnder modulator. The optical modulator modulates light output from a laser based on the drive signals to supply optical subcarriers corresponding to the digital subcarriers. These optical subcarriers may be received by optical receivers provided at different locations in an optical communications network, where the optical subcarrier may be processed, and the input data stream associated with such optical subcarrier is output. Accordingly, instead of providing multiple lasers and modulators, for example, data is carried by individual subcarriers output from an optical source including one laser and modulator. Thus, a cost associated with the network may be reduced. Moreover, each of the subcarriers may be detected by a corresponding one of a plurality of receivers, each of which being provided in a different location in the optical communication network. Thus, receivers need not be co-located, such that the network has improved flexibility.

A polarization recovery device comprises an input that receives a first optical signal with unknown polarization and with at least one signal parameter at an initial value, a first output that outputs a second optical signal with known polarization and with the at least one signal parameter at or near the initial value, and a recovery block that generates the second optical signal based on the first optical signal.

A polarization recovery device comprises an input that receives a first optical signal with unknown polarization and with at least one signal parameter at an initial value, a first output that outputs a second optical signal with known polarization and with the at least one signal parameter at or near the initial value, and a recovery block that generates the second optical signal based on the first optical signal.

Provided are, among other things, systems, methods and techniques for providing remote location-based customer service for in-store customers. One such system includes: (a) a central server; (b) wireless transceivers coupled to the central server at different locations within each of multiple different retail shopping sites; and (c) handheld wireless devices, carried by customers at such retail shopping sites and in wireless communication with such wireless transceivers. Each of the handheld wireless devices is configured with a user interface that allows a customer to designate a user-interface element to request a customer-service session. Upon designation of the user-interface element on one of such handheld wireless devices, the request is forwarded to the central server. The central server establishes a two-way real-time communication link between the handheld wireless device and a customer-service representative.

A difference frequency generation optical transmitter and sum frequency generation optical receiver operating in the mid-infrared wavelength range for use in free space optical satellite communications are described. By using mid-infrared light, the transmitter/receiver can mitigate atmospheric scintillation, scattering, and other non-ideal optical effects in the communication channel. This is achieved through the use of nonlinear optical crystals designed for difference frequency generation in the case of the transmitter and sum frequency generation for the receiver. High-speed modulated communication signals can thus be frequency converted to the mid-infrared wavelength range by a relatively low cost, compact and high-power optical communication system.

A system, comprising an optical transmitter configured to modulate a pulsed laser signal based on a plurality of data signals to form a plurality of modulated optical data signals, optical time division multiplex the plurality of modulated optical data signals to obtain a multiplexed optical data signal, and transmit the multiplexed optical data signal together with an optical clock signal derived from the pulsed laser signal; and an optical receiver that includes a clock recovery branch configured to recover the optical clock signal into a plurality of phase-shifted recovered optical clock signals and a data branch with a plurality of saturable absorbers (SA), each SA being in optical communication with one of the phase-shifted recovered optical clock signals and configured to receive the multiplexed optical data signal and to transmit of one of the plurality of modulated optical data signals according to the recovered optical clock signal.