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.

A modified optical PAM communication system using multiple laser sources to generate each amplitude level. The systems can be applied separately or in conjunction with another modulation system such as SDM, MDM, WDM, TDM, or other communication systems. In an embodiment, a PAM-4 system will increase data rate by a factor of two, but more complicated schemes using more lasers can be utilized to generate higher efficiency schemes. For example, a 25 Gbps NRZ signal will give 50 Gbps PAM-4 signal and higher laser systems can generate PAM-8 or PAM-16 for 75 and 100 Gbps systems respectively. These can be further applied to SDM systems to generate higher data rates equivalent to the number of SDM channels multiplied by the PAM efficiency. In embodiments, the invention may combing PAM with WDM and SDM to achieve multiple bits per symbol.

Signal distribution arrangements are assembled by selecting a terminal body and a tap module combination that provides the desired signal strength at the intended position in an optical network. Each terminal body includes an input connection interface, a pass-through connection interface, a module connection interface, and multiple drop connection interfaces. Each tap module houses an optical tap having an asymmetric split ratio. Most of the optical signal power received at the signal distribution arrangement passes to the pass-through connection interface. A portion of the optical signal power is routed to the drop connection interfaces (e.g., via a symmetrical optical power splitter). The tap module and terminal body combination are selected based on the desired number of drop connection interfaces and to balance the asymmetric split ratio with the symmetric split ratio.

Systems and methods include, responsive to a request for capacity change of X channels, X is an integer >1, on an optical section (14) and at an Optical Add/Drop Multiplexer (OADM) node (12) in an optical network (10), dividing optical spectrum on the optical section into M slots, M is an integer >1, such that the capacity change of X channels takes a maximum of N steps, N is an integer >1; and performing the capacity change of X channels in up to the N steps in an interleaved manner that changes a subset of the X channels in each of the N steps. For each step, the performing can include a maximum of M/N slots of the M slots with spacing between each of the M/N slots not used for the capacity change in a corresponding step. The spacing can be f, (N+f), (2N+f), . . . , M over the optical spectrum, where f is each step, f=1, 2, . . . , N.

This disclosure describes devices and methods related to multiplexing optical datasignals. A method may be disclosed. The method may comprise receiving, by a dense wave division multiplexer (DWDM), one or more optical data signals. The method may comprise combining, by the DWDM, the one or more optical data signals. The method may comprise outputting, by the DWDM, the combined one or more optical data signals to a first circulator. The method may also comprise combining, by the WDM, the second optical data signal and one or more third signals, and outputting an egress optical data signal to an optical switch. The method may also comprise outputting, by the optical switch, the egress optical data signal on a primary fiber.

A system comprising an optical receiver for multi-wavelength-channel optical communication, an optical source of spontaneous emission light and a tunable optical filter connected to receive the light at an input. The tunable optical filter can have a filter spectrum with spectral passbands separated by spectral notches. The system also includes an optical fiber link connecting an output of the optical filter to the optical receiver for multi-wavelength-channel optical communication. The receiver can be configured to make a measurement indicative of an optical power level in at least one of the notches or to make measurements of optical power levels and at least one of the passbands and at least one of the notches in response to the optical source transmitting the filtered light to the optical fiber link. Another embodiment includes an apparatus comprising an optical test module including a source of spontaneous emission light and an optical filter connected to receive the spontaneous emission light from the source.

A common component assembly is provided for a cable joint for joining a first submarine optical cable and a second submarine optical cable. The assembly includes a first end face including a first opening and a first flange for connection to a first cable termination unit of an undersea optical cable joint. The assembly also includes a second end face including a second opening and a second flange for connection to a second cable termination unit of an undersea optical cable joint. The assembly further includes a fiber tray connecting the first end face to the second end face. In addition, the assembly includes an optical assembly connected to a first side of the fiber tray. The optical assembly includes a free space optical add/drop multiplexer.

A coherent optical transmitter configured to generate a modulated optical signal within a portion of optical spectrum defined by a spectral position and spectral width, wherein the spectral width is ‘n’ bins where n is an integer greater than 1 and each bin is a same size, and wherein the spectral position and spectral width are specified by to the coherent optical transmitter via a management system.

In order to provide a submarine optical transmission system that utilizes multiple wavelength bands, the submarine branching apparatus is provided with: a first demultiplexing part for demultiplexing a wavelength-multiplex optical signal input from a first terminal station into a first wavelength-multiplex optical signal and a second wavelength-multiplex optical signal; an optical add-drop part for outputting at least a third wavelength-multiplex optical signal included in the first wavelength-multiplex optical signal to a second terminal station, and for outputting a fifth wavelength-multiplex optical signal by multiplexing at least a fourth wavelength-multiplex optical signal included in the first wavelength-multiplex optical signal with a wavelength-multiplex optical signal input from the second terminal station; and a first multiplex part for multiplex the second wavelength-multiplex optical signal with the fifth wavelength-multiplex optical signal input from the optical add-drop part and outputting the resulting signal to a third terminal station.

The disclosed systems and methods support addition of bands to a multi-band optical interface. The systems and methods can include a multi-band interface device for optical networks. The device can include a multi-band optical amplifier, a C-Band Add/Drop multiplexer, an L-Band Add/Drop multiplexer and an amplifier noise source. The multi-band optical amplifier can be connected to the C-Band Add/Drop multiplexer and connected to the L-Band Add/Drop multiplexer through the amplifier noise source. The amplifier noise source be configured to generate a combination of bulk noise and an input transmission received from the L-Band Add/Drop multiplexer. The gain of the amplifier noise source can depend on the power of the received input transmission. The power of the received input transmission can be increased over a period of time, transitioning the amplifier noise source from acting as a bulk noise source to acting an amplifier.