[Problem] To reduce a filter penalty caused by narrowing of an optical signal band due to optical filters having a multiplexing/demultiplexing function in an optical transmission line between transponder units. [Solution] In an optical transmission system 10A, transponder units 21a to 21n and 22a to 22n connected by optical fibers 14 in which optical filters having a multiplexing/demultiplexing function of an optical signal are interposed include a transmission unit 22 that transmits the optical signal obtained by modulating laser light from a laser light source 34 with an electric signal from a communication apparatus to the optical fibers 14, and a reception unit 23 that receives the optical signal from the optical fibers 14 and converts the received optical signal into an electric signal. The reception unit 23 includes a BER measurement unit that measures a BER, based on a received signal, and feeds the measured BER back to a transmitting side. The transmission unit 22 includes a frequency shift control unit that performs frequency shift control of making a center frequency of the laser light match a center frequency of the received optical signal so that the fed back BER is minimized.

The present disclosure relates to the field of microwave and optoelectronic technologies, and in particular to an integrated microwave photon transceiving front-end for a phased array system, including: a ceramic substrate, on which a control integrated circuit, a silicon-based photonic integrated chip, a first amplifying chipset, a second amplifying chipset, and a microwave switch chipset are carried. The control integrated circuit is configured to control the silicon-based photonic integrated chip and the microwave switch chipset by means of an input control signal. The silicon-based photonic integrated chip is connected at one end with an input/output optical fiber, and at the other end with the first amplifying chipset and the second amplifying chipset. The two amplifying chipsets are connected to the microwave switch chipset respectively, and the microwave switch chipset is further connected with a phased array antenna.

An apparatus includes a first reconfigurable optical add/drop multiplexer (ROADM) to receive a first optical signal and a second ROADM to receive a second optical signal. The apparatus also includes a reconfigurable optical switch that includes a first switch, switchable between a first state and a second state, to transmit the first optical signal at the first state and block the first optical signal at the second state. The reconfigurable optical switch also includes a second switch, switchable between the first state and the second state, to transmit the second optical signal at the first state and block the second optical signal at the second state. The reconfigurable optical switch also includes an output port to transmit an output signal that is a sum of possible optical signals transmitted through the first switch and the second switch.

An optical signal transmission system comprising a multimode optical fiber link. The multimode optical fiber link is for transmission of a plurality of optical signals in a plurality of spatial modes supported by the multimode optical fiber link. The optical signal transmission system comprises a photonic device in the form of a spatial mode add drop multiplexer coupled to the multimode optical fiber link and configured for at least one of coupling into the multimode optical fiber link an optical signal of the plurality of optical signals into a spatial mode of the plurality of spatial modes and coupling out of the multimode optical fiber link and into an optical fiber the optical signal of the spatial mode.

Embodiments of this application disclose an optical switch. The optical switch includes at least one first port, at least one second port, a first wavelength division multiplexing WDM apparatus, an optical splitter, an optical monitoring apparatus, and an optical switching apparatus. The first port is configured to transmit an input first optical signal to the first WDM apparatus, where the first optical signal is a multi-wavelength signal. The first WDM apparatus is configured to demultiplex the first optical signal. The optical splitter is configured to split a demultiplexed first optical signal to obtain a first sub-signal and a second sub-signal. The optical switching apparatus is configured to perform optical switching on the first sub-signal. The second port is configured to output a first sub-signal obtained after optical switching. The optical monitoring apparatus is configured to perform optical performance monitoring on the second sub-signal.

A data center network system and a signal transmission system, where the signal transmission system includes one hub device, at least two switches, multiple colored optical modules, at least two multiplexers/demultiplexers, and at least two servers. The hub device, the at least two switches, the multiple colored optical modules, the at least two multiplexers/demultiplexers, and the at least two servers form a star network topology structure.

Methods and systems for selectable parallel optical fiber and WDM operation may include an optoelectronic transceiver integrated in a silicon photonics die. The optoelectronic transceiver may, in a first communication mode, communicate continuous wave (CW) optical signals from an optical source module to a first subset of optical couplers on the die for processing signals in optical modulators in accordance with a first communications protocol, and in a second communication mode, communicate the CW optical signals to a second subset of optical couplers for processing signals in the optical modulators in accordance with a second communications protocol. Processed signals may be transmitted out of the die utilizing a third subset of the optical couplers. First or second protocol optical signals may be received from the fiber interface coupled to a fourth subset or a fifth subset, respectively, of the optical couplers.

Methods and systems for a bi-directional receiver for standard single-mode fiber based on grating couplers may include, in an integrated circuit, a multi-wavelength grating coupler, and first and second optical sources coupled to the integrated circuit: coupling first and second source optical signals at first and second wavelengths into the photonically-enabled integrated circuit using the first and second optical sources, where the second wavelength is different from the first wavelength, receiving a first optical data signal at the first wavelength from an optical fiber coupled to the multi-wavelength grating coupler, and receiving a second optical data signal at the second wavelength from the optical fiber. Third and fourth optical data signals at the first and second wavelengths may be communicated out of the optoelectronic transceiver via the multi-wavelength grating coupler.

A multiplexer/demultiplexer and a passive optical network system are provided. The multiplexer/demultiplexer includes N optical multiplexing/demultiplexing modules. The optical multiplexing/demultiplexing modules multiplex signals with different wavelengths from a plurality of ports to a same port, or demultiplex signals with different wavelengths from one port to different ports. The N optical multiplexing/demultiplexing modules correspond to the signals with different wavelengths. In the optical multiplexing/demultiplexing modules, a negative dispersion amount and an insertion loss of an M.sup.th optical multiplexing/demultiplexing module are less than those of an (M+1).sup.th optical multiplexing/demultiplexing module, where N is a positive integer, and M is a positive integer less than or equal to N. The multiplexer/demultiplexer and the passive optical network system increase an optical power budget between an optical transmitter and an optical transceiver.

An optical network packet configured to transmit over an optical communication link from a first optical network having a first control plane to a second optical network having a second control plane is generated. Generating the optical network packet comprises generating the packet configured to be transmitted from the first optical network to the second optical network in the optical domain.