Abstract: Methods and systems for optical signal grooming that include providing one or more input signals, each having one or more modulated subcarriers, to a grooming processor; and grooming the input signals at a subcarrier level with the grooming processor to produce one or more output signals by arranging the modulated subcarriers in the output signals according to a grooming operation such that the modulated subcarriers are not demodulated or decoded prior to grooming.

Abstract: A method for optical layer traffic grooming includes receiving at least two optical input signals into respective optical receivers, each optical receiver having a photodetector for converting the respective optical input signal into a respective electrical signal; a grooming processor responsive to the electrical signals, the grooming processor being a radio frequency RF processor for processing the electrical signals at a subcarrier level to produce an RF orthogonal frequency division multiplexing signal OFDM signal; and modulating the groomed RF OFDM signal at a transmitter for conversion of the groomed RF OFDM into an optical signal.

Abstract: A method for transponder optical channel selection of optical signals from a transponder aggregator includes choosing wavelength division multiplexing channels to be dropped from a transponder aggregator receiving optical input signals, splitting all dropped wavelength division multiplexing channels into at least one transponder having a coherent receiver and transmitter, and tuning a local oscillator laser of the coherent receiver to a wavelength of one of the all dropped wavelength division multiplexing channels for selecting one of the all dropped wavelength division multiplexing channels.

Abstract: ROADM node systems and methods of operation are disclosed. ROADM node systems may include transponder aggregators including transponders to add signals for switching through the ROADM node. The transponder aggregators include optical couplers constrained that are from coupling added signals on adjacent channels for simultaneous use. The ROADM system may include an optical interleaver that can provide an additional filtering function for the coupled signals prior to transmission of the signals on a WDM network.

Abstract: An optical receiver system is disclosed. The system includes a local oscillator, a mixer and a processor. The local oscillator is configured to generate a laser signal to indicate a selection of one of a plurality of channels. In addition, the mixer is configured to receive signals on the plurality of channels and to utilize the laser signal to distinguish the signal on the selected channel. Further, the processor is configured to maximize a power level difference between the laser signal and at least one of the plurality of channels based on a total number of the plurality of channels by adjusting the power of the laser signal input to the mixer to limit a noise penalty in the receiver system.

Abstract: ROADM node systems and methods of operation are disclosed. ROADM node systems may include transponder aggregators including transponders to add signals for switching through the ROADM node. The transponder aggregators may be constrained from adding signals on adjacent channels for simultaneous use. Further, the transponder aggregators may include an optical coupler in lieu of an optical multiplexer. The ROADM system may include a set of wavelength selective switches associated with output ports that can provide an additional filtering function for the added signals prior to transmission on a WDM network.

Abstract: In a dense wavelength division multiplexed optical network, an upgradeable, modular, colorless, directionless, reconfigurable add/drop multiplexer having a small form factor. By using wavelength selective switches and couplers, the above features are achieved without the need for photonic cross connects.

Abstract: A modular wavelength cross connect node for use in a dense wavelength division multiplexing network exhibiting low cost and improved performance by employing a bidirectional wavelength selective switch in a main optical path and using optical circulators to share any common ports.

Abstract: Disclosed is transponder (optical transmitter/receiver) that has a switch, which switches on and off the loopback of an optical path, to allow the same transponder to implement the transmission/reception end function on an optical path, and the regenerative repeating function at an intermediate point on an optical path. When a new optical path is built, the assignment of the wavelength and the allocation of the incoming and outgoing paths for transmission/reception are set remotely. (FIG.

Abstract: The present invention provides a redundant switching system capable of continuing to construct an uninterrupted redundant configuration. The redundant switching system 100 includes at least two pathways (e.g. pathways 10-1 and 10-2) that construct an uninterrupted redundant configuration, and allow uninterrupted pathway switching. In the event that a failure occurs in either (pathway 10-1) of the two pathways (10-1 and 10-2), another pathway (pathway 10-3) allowing uninterrupted pathway switching for the pathway (pathway 10-2) where a failure did not occur is prepared. Then an uninterrupted redundant configuration is reconstructed by means of the pathway where a failure did not occur (pathway 10-2) and the other pathway (pathway 10-3).

Abstract: An optical level calculator calculates optical powers of individual wavelengths of a through wavelength division multiplexed signal based on an input level monitor, network information, and insertion loss information 5, and obtains an optimum level for an add signal. An optical level controller controls a power of the add optical signal to the optimal level based on the calculated result, and multiplexes the through wavelength division multiplexed signal and the add optical signal.

Abstract: Disclosed is a core network system which performs bi-directional optical transmission, including: a first transmission path for transmitting an optical signal, which is wavelength division-multiplexed, toward subscriber terminals from the core network; and a second transmission path for transmitting an optical signal, which is wavelength division-multiplexed, from the subscriber terminals to the core network; wherein transmission capacity of the second transmission path is lessen rather than transmission capacity of the first transmission path in agreement with asymmetry of traffic of the second transmission path to the first transmission path. Further, optical transmission equipment which constructs the core network system is also disclosed.

Abstract: A wavelength division multiplex transmitter is provided, which is capable of automatically setting up the number of wavelengths and detecting a trouble in a transmission path, and so making a WDM transmission with always keeping the whole of the system at the optimum level. In a WDM system, light detection monitors are provided in the light signal input part of an AWG module, and the number of wavelengths to be multiplexed is determined based on the light input powers.

Abstract: An optical level calculator calculates optical powers of individual wavelengths of a through wavelength division multiplexed signal based on an input level monitor, network information, and insertion loss information 5, and obtains an optimum level for an add signal. An optical level controller controls a power of the add optical signal to the optimal level based on the calculated result, and multiplexes the through wavelength division multiplexed signal and the add optical signal.