A method of automatically tuning subcarriers of a superchannel transmission. The method comprises determining (71) a received parameter of transmission quality of one or more of the plurality of subcarriers. The method further comprises tuning (72) a frequency of the one or more subcarrier based on the determined parameter of the transmission quality.

A module, system and method adjusts a tunable filter to have an adjustable frequency response based on one of an outbound optical signal on a transmit channel and an inbound optical signal on a receive channel. The tunable filter is in an optical path of the outbound optical signal and in an optical path of the inbound optical signal. The transmit and the receive channels are configured as part of a channel plan of a bidirectional (bi-di) dense wavelength division multiplexing (DWDM) system.

A wavelength division multiplexing, WDM, network comprising an apparatus adapted to manage a frequency spectrum in the wavelength division multiplexing, WDM, network, the apparatus comprising an adjustment unit adapted to adjust a frequency offset between carriers for each individual carrier depending on performance characteristics of the individual carriers.

Methods and systems for optimizing the transmission of superchannels with different modulation formats may include pre-calculating different guardband (GB) values between superchannels and sets of power values for subcarriers to implement subcarrier power pre-emphasis (SPP). When a request for an optical path is received at a network management system, the spectral allocation of each superchannel, including a GB, is determined according to pre-specified rules based on co-propagation of the superchannels with different modulation formats.

A wavelength-selective device includes: a storage in which a wavelength management table is stored; and a processor configured to execute a procedure, the procedure including: searching for one or more paths used as a new path having a first ending time in a network, based on the wavelength management table; selecting a wavelength having a second ending time closest to the first ending time, from one or more wavelengths used on paths found by the searching; and configuring a path using the selected wavelength as the new path.

An optical transmitter includes a frequency comb light source; a demultiplexer configured to demultiplex light output from the frequency comb light source into n channels (n is an integer of 2 or greater) at a wavelength interval ; and n filters respectively connected to n output ports of the demultiplexer, the n filters being configured to reduce a high-order spectral component for each wavelength.

In an optical network based on a dense wavelength division multiplexing system using a flexible frequency grid, it is difficult to improve the usage efficiency of an optical frequency band owing to the occurrence of fragmentation of the optical frequency band; therefore, an optical network controller according to an exemplary aspect of the present invention includes an optical frequency region setting means for dividing an optical frequency band used in an optical network based on a dense wavelength division multiplexing system using a flexible frequency grid, and setting a plurality of optical frequency regions; and an optical path setting means for setting optical paths having a common attribute in at least one of the plurality of optical frequency regions.

Systems and methods for determining minimal spectrum occupancy in routing and wavelength/spectrum assignment (RWA/RSA) in an optical network include performing, for a new demand request, a set of binary operations using a binary representation for each wavelength or portion of spectrum over all links in the optical network; and selecting, based on the set of binary operations, i) a route and ii) one of a) a wavelength and b) one or more portions of spectrum for the new demand request.

Methods and systems are provided for optical signal transmission using span-wise spectrum management. The method includes transmitting a first optical signal at a first wavelength by a control system. The first optical signal has a first optical path distance. The method further includes determining a first guard band requirement for the first optical signal, and transmitting a second optical signal by the control system. The second optical signal has a second optical path distance. The method includes determining a second guard band requirement for the second optical signal, and placing the second optical signal spectrally adjacent to the first optical signal by selecting a second wavelength. The second wavelength is selected to satisfy the first and second guard band requirements.

The example embodiments presented herein are directed towards an Optical Network Element, ONE, node (14), and corresponding method therein, for establishing multiple spectral routing in an optical transport network. The establishment of the multiple spectral routing features the use of a Split-Spectrum Label, SSL, (11) which comprises multiple definitions for spectral slots, where each definition has an absolute starting and an absolute ending frequency allocation.