Abstract: A method and device for compensating, within a node of an optical network, chromatic dispersion undergone by optical packets transmitted within time slots of wavelength division multiplexed channels along at least one link of the optical network, a time slot duration corresponding to the sum of a packet duration and an inter-packet gap duration. The method and device demultiplexes the wavelength division multiplexed channels into a plurality of bands, and transmits the bands, via a respective plurality of delay lines having predetermined delays, toward a respective plurality of packet add/drop structures comprising a coherent receiver.

Abstract: Proposed is a method of optical data transmission. The method comprises different steps. A first optical signal and a second optical signal are generated, such that the optical signals possess a same wavelength, respective phases, which are modulated in dependence on respective data values, and respective polarization states, which are essentially orthogonal to each other. A combined optical signal is generated, by combining the optical signals, such that the combined optical signal possesses a polarization state with a predetermined variation. The combined optical signal is transmitter over an optical transmission line and received. Two time-discrete sampled signals are generated, by sampling the received optical signal along two orthogonal polarization planes. Two filtered signals are generated, by filtering the time-discrete sampled signals in the time-discrete domain, using a function that is indicative of the respective predetermined variation.

Abstract: Data is transmitted using multiple phase-modulated optical wavelength division multiplexed signals carrying respective synchronous data packet sequences. The data packet sequences comprise data packets within respective data packet time slots. The data packet time slots are separated by guard band time slots. Within at least one of the optical WDM signals, a data packet is detected. A time-discrete electrical signal is derived from the one optical WDM signal, by down converting the one optical WDM signal using a local oscillator optical signal. A first discrete spectral component of the time-discrete electrical signal is determined, which corresponds to a direct current component of the time-discrete electrical signal. A second discrete spectral component of the time-discrete electrical signal is determined, which corresponds to a symbol rate of the one optical WDM signal. A data packet is detected, in the case that a fraction between the spectral components exceeds a predefined threshold.

Abstract: Proposed is a method of demodulating a phase modulated optical signal received from an optical channel. A time-discrete electrical signal is derived from the phase modulated optical signal, using a local optical signal, which has a frequency that is essentially equal to a carrier frequency of the phase modulated optical signal. A phase error between the local optical signal and the phase modulated optical signal is compensated, by deriving from the local optical signal a phase offset and modifying the derived time-discrete electrical signal by this phase offset. A chromatic dispersion caused by the optical channel is compensated, by filtering the modified time-discrete electrical signal using a digital filter.

Abstract: Proposed is an optical node that contains a number of A optical demultiplexers. Each demultiplexer is adapted to provide at its N output ports N incoming optical signals received from N optical cores of an incoming optical multi-core fiber. Furthermore, the optical node contains a number of B optical multiplexers. Each multiplexer is adapted to receive at its N input ports N outgoing optical signals and to insert the N outgoing optical signals into N optical cores of an outgoing multi-core fiber. The optical node is configurable to switch one of the incoming optical signals simultaneously onto B input ports of different multiplexers and to combine A of the incoming optical signals from A output ports of different demultiplexers onto a same input port of one of the multiplexers. Alternatively, N incoming signals are received from N different mode signals of a spatially multiplexed multi-mode fiber and then transmitted as N multi-mode signals into a spatially multiplexed multi-mode fiber.

Abstract: A optical transmitter and method for transmitting digital data on an optical channel, performing the steps of generating first and second baseband digital signals, modulating a first polarized optical carrier wave component in accordance with the first baseband digital signal, modulating a second polarized optical carrier wave component in accordance with the second baseband digital signal, wherein the second polarized optical carrier wave component has an orthogonal polarization to the first polarized optical carrier wave component and combining the first and second modulated optical carrier wave components into a propagation medium. The first and second baseband digital signals are generated in a correlated manner so that the modulated optical carrier wave components are combined as a modulated single-polarization optical carrier wave.

Abstract: Proposed is a method of optical data transmission. A first data signal and a second data signal are received at a same sampling rate. A third data signal and a fourth data signal are generated, using the first and the second data signal, wherein the two data signals are delayed to each other by a delay time that is varied over time. The phase of a first optical signal is modulated in dependence on the third data signal, and the phase of a second optical signal with a same wavelength is modulated in dependence on the fourth data signal. The first optical signal is transmitted in a first polarization plane into an optical fiber, and the second optical signal is transmitted in a second polarization plane orthogonal to the first polarization plane into the optical fiber.

Abstract: A method and device for compensating, within a node of an optical network, chromatic dispersion undergone by optical packets transmitted within time slots of wavelength division multiplexed channels along at least one link of the optical network, a time slot duration corresponding to the sum of a packet duration and an inter-packet gap duration. The method and device demultiplexes the wavelength division multiplexed channels into a plurality of bands, and transmits the bands, via a respective plurality of delay lines having predetermined delays, toward a respective plurality of packet add/drop structures comprising a coherent receiver.

Abstract: The embodiments of the present invention describe a method for optimizing the capacity of an optical communication network that uses wavelength division multiplexing, wherein the spectral distribution of the signals intended to be transmitted over a plurality of channels is done dynamically through the use of a variable spectrum grid whose spectral spacings between two successive channels are determined based on the spectral width of said signals and in which dynamic filtering of said signals is carried out before their transmission in order to adjust their spectral width based on the available spectral space, and thereby reduce crosstalk between adjacent channels when the signals are transmitted.

Abstract: Proposed is an optical node that contains a number of A optical demultiplexers. Each demultiplexer is adapted to provide at its N output ports N incoming optical signals received from N optical cores of an incoming optical multi-core fiber. Furthermore, the optical node contains a number of B optical multiplexers. Each multiplexer is adapted to receive at its N input ports N outgoing optical signals and to insert the N outgoing optical signals into N optical cores of an outgoing multi-core fiber. The optical node is configurable to switch one of the incoming optical signals simultaneously onto B input ports of different multiplexers and to combine A of the incoming optical signals from A output ports of different demultiplexers onto a same input port of one of the multiplexers. Alternatively, N incoming signals are received from N different mode signals of a spatially multiplexed multi-mode fiber and then transmitted as N multi-mode signals into a spatially multiplexed multi-mode fiber.

Abstract: Proposed is a method of demodulating a phase modulated optical signal received from an optical channel. A time-discrete electrical signal is derived from the phase modulated optical signal, using a local optical signal, which has a frequency that is essentially equal to a carrier frequency of the phase modulated optical signal. A phase error between the local optical signal and the phase modulated optical signal is compensated, by deriving from the local optical signal a phase offset and modifying the derived time-discrete electrical signal by this phase offset. A chromatic dispersion caused by the optical channel is compensated, by filtering the modified time-discrete electrical signal using a digital filter.

Abstract: Proposed is a method of optical data transmission. The method comprises different steps. A first optical signal and a second optical signal are generated, such that the optical signals possess a same wavelength, respective phases, which are modulated in dependence on respective data values, and respective polarization states, which are essentially orthogonal to each other. A combined optical signal is generated, by combining the optical signals, such that the combined optical signal possesses a polarization state with a predetermined variation. The combined optical signal is transmitter over an optical transmission line and received. Two time-discrete sampled signals are generated, by sampling the received optical signal along two orthogonal polarization planes. Two filtered signals are generated, by filtering the time-discrete sampled signals in the time-discrete domain, using a function that is indicative of the respective predetermined variation.

Abstract: A optical transmitter and method for transmitting digital data on an optical channel, performing the steps of generating first and second baseband digital signals, modulating a first polarized optical carrier wave component in accordance with the first baseband digital signal, modulating a second polarized optical carrier wave component in accordance with the second baseband digital signal, wherein the second polarized optical carrier wave component has an orthogonal polarization to the first polarized optical carrier wave component and combining the first and second modulated optical carrier wave components into a propagation medium. The first and second baseband digital signals are generated in a correlated manner so that the modulated optical carrier wave components are combined as a modulated single-polarization optical carrier wave.

Abstract: Proposed is a method of optical data transmission. A first data signal and a second data signal are received at a same sampling rate. A third data signal and a fourth data signal are generated, using the first and the second data signal, wherein the two data signals are delayed to each other by a delay time that is varied over time. The phase of a first optical signal is modulated in dependence on the third data signal, and the phase of a second optical signal with a same wavelength is modulated in dependence on the fourth data signal. The first optical signal is transmitted in a first polarization plane into an optical fibre, and the second optical signal is transmitted in a second polarization plane orthogonal to the first polarization plane into the optical fibre.

Abstract: The embodiments of the present invention describe a method for optimizing the capacity of an optical communication network that uses wavelength division multiplexing, wherein the spectral distribution of the signals intended to be transmitted over a plurality of channels is done dynamically through the use of a variable spectrum grid whose spectral spacings between two successive channels are determined based on the spectral width of said signals and in which dynamic filtering of said signals is carried out before their transmission in order to adjust their spectral width based on the available spectral space, and thereby reduce crosstalk between adjacent channels when the signals are transmitted.