Wavelength-based random access in an optical communications network for a wireless communications system (WCS) is disclosed. An optical network unit(s) (ONU(s)) is configured to generate a random access signal comprising an unsolicited buffer occupancy (BO) report to request uplink allocation as soon as the ONU(s) receives a non-periodic uplink data burst. The ONU(s) then sends an optical random access signal including the unsolicited BO report to an optical line terminator (OLT) based on a random access wavelength, which is so determined not to cause any interference with a downlink optical communications signal(s) and an uplink optical communications signal(s) being regularly communicated between the OLT and the ONU(s). As a result, it is possible to reduce access delay at the ONU(s) for sending the non-periodic uplink data burst without requiring frequent polling from the OLT, thus helping to reduce signaling overhead and improve throughput of the optical communications network.

An optical beamforming device includes an RF front-end transmitting or receiving RF signals and an optical beamformer forming or compensating for a time delay for each of the plurality of channels based on the RF signals. The optical beamformer includes E/O converters converting the RF signals into optical signals, respectively, a linear modulator generating an optical modulation signal based on an RF input signal, a TTD array outputting an optical combined signal obtained by compensating for a time delay degree of the input optical signals or outputting output optical signals, in each of which a time delay is formed for each channel, by distributing the optical modulation signal, a photo detector generating an RF output signal to an RF back-end based on the optical combined signal, and O/E converters converting the output optical signals into RF signals, respectively.

Today's communications require an effective yet scalable way interconnection of data centers and warehouse scale computers (WSCs) whilst operators must provide a significant portion of data center and WSC applications free of charge to users and consumers. At present, data center operators face the requirement to meet exponentially increasing demand for bandwidth without dramatically increasing the cost and power of the infrastructure employed to satisfy this demand. Simultaneously, consumer expectations of download/upload speeds and latency in accessing content provide additional pressure. Accordingly, the inventors provide a number of optical switching fabrics which reduce the latency and microprocessor loading arising from the prior art Internet Protocol multicasting techniques.

Described are various configurations of reduced crosstalk optical switches. Various embodiments can reduce or entirely eliminate crosstalk using a coupler that has a power-splitting ratio that compensates for amplitude imbalance caused by phase modulator attenuation. Some embodiments implement a plurality of phase modulators and couplers as part of a dilated switch network to increase overall bandwidth and further reduce potential for crosstalk.

A wavelength cross-connect device performs a relay process in which multiple wavelength signal light beams that have been transmitted in multiple bands from a plurality of paths and demultiplexed into optical signals in the respective wavelength bands for each path are amplified, are switched to paths by contention WSSs, and are output to paths on the output side. A WXC unit performs the relay process on an optical signal in a specific wavelength band An input-side conversion unit that converts a wavelength band other than the specific wavelength band into the specific wavelength band is provided on the input side, and an output-side conversion unit that converts the specific wavelength band after the conversion into the wavelength band prior to the conversion is provided on the output side. A directly-input optical signal in the specific wavelength band is directly output after the relay process at the WXC unit.

An optical switch is proposed, for routing an optical transmission signal according to an optical control signal, including one or more optical control ports; three or more optical transmission ports; a light director; and a thermally driven light mill; where the light mill and the light director are arranged with respect to each other, to the one or more control ports and to the three or more transmission ports such that: illumination of a respective one of the one or more control ports by a control beam carrying the control signal drives the light mill to rotate towards a respective position in which the light director is arranged so as to direct a transmission beam carrying the transmission signal, entering the switch via a respective one of the transmission ports, to exit the switch via a respective other of the transmission ports.

This disclosure describes C and L band optical communications module link extender, and related systems and methods. An example method may include receiving, by a first dense wave division multiplexer (DWDM) of an amplification module in communication with an optical communication module link extender (OCML), first passive optical network (PON) signals in a downstream direction. The example method may also include combining the first PON signals into a combined PON signal, and outputting the combined PON signal to the OCML. The example method may also include receiving, by a first input of the OCML, the combined PON signal. The example method may also include receiving by a second dense wave division multiplexer (DWDM) of the OCML, one or more optical data signals in the downstream direction, the one or more optical data signals being a different signal type than the one or more PON signals. The example method may also include combining, by the second DWDM, the one or more optical data signals into a combined optical data signal, and outputting the combined optical data signal. The example method may also include outputting, by the OCML, the combined optical data signal and the combined PON signal. The example method may also include receiving, from the amplification module and from the OCML, a second combined PON signal in an upstream direction at one or more Raman pumps of the amplification module. The example method may also include outputting, by the one or more Raman pumps, the second combined PON signal to the first DWDM.

A network or system in which a hub or primary node may communicate with a plurality of leaf or secondary nodes. The hub node may operate or have a capacity greater than that of the leaf nodes. Accordingly, relatively inexpensive leaf nodes may be deployed to receive data carrying optical signals from, and supply data carrying optical signals to, the hub node. One or more connections may couple each leaf node to the hub node, whereby each connection may include one or more spans or segments of optical fibers, optical amplifiers, optical splitters/combiners, and optical add/drop multiplexer, for example. Optical subcarriers may be transmitted over such connections, each carrying a data stream. The subcarriers may be generated by a combination of a laser and a modulator, such that multiple lasers and modulators are not required, and costs may be reduced. As the bandwidth or capacity requirements of the leaf nodes change, the number of subcarriers, and thus the amount of data provided to each node, may be changed accordingly. Each subcarrier within a dedicated group of subcarriers may carry OAM or control channel information to a corresponding leaf node, and such information may be used by the leaf node to configure the leaf node to have a desired bandwidth or capacity.

A device for scanning measurement of a distance to an object has a light source, which generates an optical output signal having a time-varying frequency. The device includes multiple optical processing units, which are connected optically in parallel to the light source. Each processing unit has an optical distribution matrix including multiple optical switches that distribute optical output signals selectively onto different optical waveguides. Optical output signals are outcoupled into the free space via free space couplers and optical output signals reflected on the object are coupled as optical measurement signals into the waveguides. A detector detects a superposition of the optical measurement signal and the optical output signal generated by the light source. A circulator directs optical output signals supplied by the light source to the distribution matrix and optical measurement signals coming from the distribution matrix to the detector.

A switch module includes a switch integrated circuit (IC), a silicon photonics chips, and a planar lightwave circuits (PLCs).