A transceiver separates wavelength-division-multiplexing (WDM) components into two groups, one of which is more sensitive to temperature than the other group. The temperature-sensitive group of optical components is implemented on a first substrate in the transceiver that has a lower thermo-optic coefficient than a second substrate in the transceiver, which contains the group of optical components that is less temperature sensitive. In particular, the first substrate, which may be glass, may include WDM components that convey optical signals having multiple carrier wavelengths. Moreover, the second substrate, such as a silicon substrate (e.g., a silicon-on-insulator platform), may include multiple parallel optical paths with optical components, in which a given optical path conveys an optical signal having a given carrier wavelength.

A dense wavelength-division multiplexing (DWDM) optical network includes an optical input port configured to receive unmodulated optical signals from the optical fiber comprising wavelength channels; one or more modulators coupled to the optical input port wherein the one or more modulators are each configured to modulate a respective first wavelength channel of the wavelength channels with respective data to produce a modulated first wavelength channel when the modulator is in a transmit state; wherein an input optical power of each modulator is kept at substantially a first level and an output optical power of the each modulator is kept at substantially a second level during operation of the modulator. A method and an optical network node are also disclosed therein.

[PROBLEM TO BE SOLVED] To uninterruptedly change a band of an optical transmission path in a line IF section, which relays a signal transmitted to an optical transmission path in a client IF section to which a communication terminal is connected, to the same band as a changed band in the client IF section without suspending the communication in the line IF section. [SOLUTION] An optical transmission system 10A performs processing for changing a band of an optical fiber 15 in a line IF section (L section) that relays a signal from an optical fiber 12 in a client IF section (C section) to the same band as that in the C section. Line IF units 24A and 24B provided on both sides of the L section set a temporary evacuation lane p as an optical lane having a band different from those of a plurality of optical lanes 0 to n in the optical fiber 15 in the L section, selects either a change-target optical lane (for example, the optical lane 0) or the temporary evacuation lane p, the change-target optical lane being provided in the optical fiber 15 in the L section and having a band to be changed to a same band as a band in the C section, while causing a buffer unit 46 to absorb a delay difference between a signal received by the change-target optical lane and a signal received by the temporary evacuation lane p, and sets the optical lane not selected to have the same band as the band in the C section.

An apparatus includes a memory and a processor operatively coupled to the memory. The processor is configured to partition a set of ports of an optical multiplexer into a set of port groups including a first port group having a first set of ports and a second port group having a second set of ports mutually exclusive from the first set of ports. The processor is configured to associate the first port group with a first router and associate the second port group with a second router. When the optical multiplexer is operatively coupled to the first router and the second router, the first router is operatively coupled to the optical multiplexer via the first set of ports and not the second set of ports, and the second router is operatively coupled to the optical multiplexer via the second set of ports and not the first set of ports.

If wavelength defragmentation is performed during the operation of an optical network, an instantaneous interruption of a network arises; consequently, data are lost; therefore, an optical network control method according to an exemplary aspect of the present invention includes monitoring a data volume of a client signal to be transmitted using a plurality of optical subcarriers; and performing synchronously, depending on a variation in the data volume, an optical subcarrier changing process of changing an active optical subcarrier, of the plurality of optical subcarriers, to be used for transmitting the client signal, and a remapping process of remapping the client signal onto an active optical subcarrier after having been changed.

An optical transmission device includes a first wavelength multiplexer, a second wavelength multiplexer, a wavelength converter and a third wavelength multiplexer. The first wavelength multiplexer multiplexes optical signals in a first wavelength band to generate first wavelength multiplexed light. The second wavelength multiplexer multiplexes optical signals in the first wavelength band to generate second wavelength multiplexed light in a first polarization. The wavelength converter converts a wavelength of the second wavelength multiplexed light from the first wavelength band into a second wavelength band by a cross phase modulation among the second wavelength multiplexed light, first pump light in a second polarization and second pump light in the second polarization. The second polarization is orthogonal to the first polarization. The third wavelength multiplexer multiplexes the second wavelength multiplexed light whose wavelength has been converted by the wavelength converter and the first wavelength multiplexed light.

A system and method for performing an in-service optical time domain reflectometry test, an in-service insertion loss test, and an in-service optical frequency domain reflectometry test using a same wavelength as the network communications for point-to-point or point-to-multipoint optical fiber networks while maintaining continuity of network communications are disclosed.

An example system includes a hub transceiver, a plurality of edge transceivers, and a control module. The control module is operable to receive, from one or more of the edge transceivers or the hub transceiver, telemetry data regarding at least one of a transmission or a receipt of data over the optical communications network, and determine, based on the telemetry data, performance characteristics regarding the optical communications network. Further, the control module is operable to transmit, based on the performance characteristics, a command to one or more of the edge transceivers or the hub transceiver to modify an operation with respect to the optical communications network.

An apparatus and method for processing a frequency offset of a pilot and a receiver where the includes: calculating a correlation function of a channel by using a receiving or received signal and a correlation length; calculating a phase to which the correlation length corresponds according to the correlation function; and calculating a corresponding slope according to phases to which at least two correlation lengths correspond when the phase to which the correlation length corresponds is greater than 2π, and estimating a frequency offset of a pilot of the channel based on the slope. Hence, estimation of a frequency offset of a pilot may be accurately achieved, thereby accurately judging channel spacing.

An arrayed waveguide grating (AWG) device for use in an optical transceiver is disclosed, and can de-multiplex an optical signal into N number of channel wavelengths. The AWG device can include an AWG chip, with the AWG chip providing a planar lightwave (PLC) circuit configured to de-multiplex channel wavelengths and launch the same into output waveguides. A region of the AWG chip may be tapered such that light traveling via the output waveguides encounters an angled surface of the tapered region and reflects towards an output interface region of the AWG chip. Thus detector devices may optically couple to the output interface region of the AWG chip directly, and can avoid losses introduced by other approaches which couple an output of an AWG to detectors by way of a fiber array or other intermediate device.