A transponder includes a multiplexing section, optical transmitters, optical receivers, an extracting section, and a warning monitor section, wherein the extracting section includes a first signal extracting unit for extracting reception data, a second signal extracting unit for extracting reception data, and a reception signal switching section. When carrier signals are in a link-establishable state, the reception signal switching section supplies reception electric signals generated by the optical receivers to the first signal extracting unit and outputs the reception data. When a carrier signal is in a non-link-establishable state, the reception signal switching section supplies a reception electric signal generated by an optical receiver using a carrier signal in the link-establishable state to the second signal extracting unit and outputs the reception data extracted by the second signal extracting unit.

An optical Internet Protocol (IP) router serves a cell-site over an optical communication network. The optical IP router transmits a network attach request having an optical node name over a control optical wavelength. The optical communication node receives an assignment of a data optical wavelength, a cell-site mode, and an Internet Protocol (IP) address over the control optical wavelength based on the optical node name. The optical communication node operates in the cell-site mode and responsively exchanges cell-site data having the IP address over the data optical wavelength.

An optical source switching apparatus including first optical sources, an optical cross-connect device, second optical sources, and a first coupler. The optical cross-connect device is connected to the first optical sources and the first coupler, and the first coupler is connected to the second optical source; both the first optical source and the second optical source are configured to output continuous optical energy, and the optical cross-connect device is configured to enable optical energy output by at least one of the first optical sources to enter the first coupler when at least one of the second optical sources fails; and the first coupler is configured to implement beam splitting of the optical energy output by the first optical source or the second optical source.

A method of generating multiple channels of optical pulses comprises: providing a continuous wave optical input having an optical power; dividing the optical power of the optical input into equal consecutive slices in the time domain; and allocating the consecutive slices sequentially to two or more optical outputs such that each output forms a channel of optical pulses of equal pulse repetition rate shifted in time relative to the or each other channel.

A transmitter can include a laser operable to output an optical signal; a digital signal processor operable to receive user data and provide electrical signals based on the data; and a modulator operable to modulate the optical signal to provide optical subcarriers based on the electrical signals. A first one of the subcarriers carriers carries first TDMA encoded information and second TDMA encoded information, such that the first TDMA encoded information is indicative of a first portion of the data and is carried by the first one of the subcarriers during a first time slot, and the second TDMA encoded information is indicative of a second portion of the data and is carried by the first one of the subcarriers during a second time slot. The first TDMA encoded information is associated with a first node remote from the transmitter and the second TDMA encoded information is associated with a second node remote from the transmitter. A second one of the subcarriers carries third information that is not TDMA encoded, the third information being associated with a third node remote from the transmitter. A receiver and system also are described.

An optical module is disclosed. The optical module includes a first downlink port, a second downlink port, a directional coupler, a optical attenuator, a first photodiode (PD), and a second PD. The directional coupler, connected to the first downlink port, is configured to receive a downlink optical signal. The second PD connected to the directional coupler, is configured to obtain a power value. If the power value is greater than a first threshold, the optical attenuator is configured to receive a attenuation control signal, and attenuate, based on the attenuation control signal, a power of an optical signal passing through the second downlink port. The first PD is configured to: convert the downlink optical signal into a downlink electrical signal, and convert the optical signal passing through the second downlink port into an electrical signal. Both the first downlink port and the second downlink port are connected to the first PD.

A highly scalable and modular automated optical cross connect switch devices which exhibit low loss and scalability to high port counts. A device for the programmable interconnection of large numbers of optical fibers (100s-1000s) is provided, whereby a two-dimensional array of fiber optic connections is mapped in an ordered and rule-based fashion into a one-dimensional array with tensioned fiber optic circuit elements tracing substantially straight lines there between. Fiber optic elements are terminated in a stacked arrangement of flexible fiber optic circuit elements with a capacity to retain excess fiber lengths while maintaining an adequate bend radius. The combination of these elements partitions the switch volume into multiple independent, non-interfering zones, which retain their independence for arbitrary and unlimited numbers of reconfigurations. The separation into spaced-apart zones provides clearance for one or more robotic actuators to enter the free volume substantially adjacent to the two-dimensional array of connectors and mechanically reconfigure connectors without interrupting other circuits.

A reduced-complexity optical packet switch which can provide a deterministic guaranteed rate of service to individual traffic flows is described. The switch contains N input ports, M output ports and N*M Virtual Output Queues (VOQs). Packets are associated with a flow f, which arrive an input port and depart on an output port, according to a predetermined routing for the flow. These packets are buffered in a VOQ. The switch can be configured to store several deterministic periodic schedules, which can be managed by an SDN control-plane. A scheduling frame is defined as a set of F consecutive time-slots, where data can be transmitted over connections between input ports and output ports in each time-slot. Each input port can be assigned a first deterministic periodic transmission schedule, which determines which VOQ is selected to transmit, for every time-slot in the scheduling frame. Each input port can be assigned a second deterministic periodic schedule, which determines which traffic flow within a VOQ is selected to transmit. Each input port can be assigned a third deterministic periodic schedule, which specifies to which VOQ an arriving packet (if any) is destined, for each time-slot in a scheduling frame. Each input port can be assigned a fourth deterministic periodic schedule, which specifies to which Flow-VOQ within a VOQ an arriving packet (if any) is destined. In this manner, each traffic flow can receive a deterministic guaranteed-rate of transmission through the switch.

A network switch and a transceiver restart method thereof are provided. The network switch is configured to connect to a transceiver to transmit and receive data packets through the transceiver. The network switch includes a power control circuit and a processor. The power control circuit is controlled to provide electrical power to the transceiver. The processor determines whether the transceiver is in an abnormal state. In response to determining that the transceiver is in the abnormal state, the processor first controls the power control circuit to stop providing the electrical power to the transceiver, and then controls the power control circuit to re-provide the electrical power to the transceiver.

A switch control unit and optical control unit, including: a digital-to-analog converter, being switchable between being coupled to a first sensing unit and being coupled to a drive unit, through a common contact pad; a sensing contact pad, coupled to a second sensing unit; an analog-to-digital converter, for sensing voltages at the contact pads when coupled to the sensing units, wherein each of the sensing units has a minimum working voltage level; and a loop switching unit, coupled between the common contact pad, the analog-to-digital converter, and the sensing contact pad, wherein when the voltage at the common contact pad is substantially higher than the minimum working voltage level, the loop switching unit conducts the common contact pad to the analog-to-digital converter to sense the voltage at the common contact pad, and the digital-to-analog converter enters a high-impedance state such that the digital-to-analog converter does not sense the voltage at the common contact pad.