Abstract: An optical network element is provided and contains a tunable laser source and a resonator coupled with the tunable laser source. The resonator has a length that determines a distance between modes of the tunable laser source and failures during a mode transition time between modes of the tunable laser source are correctable via error correction measures. Furthermore, a communication system contains such an optical network element.

Abstract: A method and a device are provided for adjusting a tunable laser of an optical network element. A wavelength of the tunable laser is adjusted by varying a current driving the tunable laser. The wavelength of the tunable laser is adjusted by varying a temperature of the tunable laser or at least a portion thereof relative to an environmental temperature.

Abstract: A method and a device for operating a laser in an optical component are provided, wherein the laser is a local oscillator of the optical component; and wherein a linewidth of the laser is broadened. Furthermore, an optical communication system is suggested comprising said optical component.

Abstract: A method for data processing in an optical network element is provided. An event of a forthcoming mode-hop of a tunable laser is detected. Furthermore, a corresponding optical network element and an optical communication system with at least one such optical network element are described.

Abstract: Bidirectional data signals are exchanged between a central unit and a plurality of network terminals. The optical carrier frequencies of the downstream and upstream signals are chosen so that reflections do not interfere with the selected signal at the optical network unit and not with the received upstream signals at the central unit. The optical network units select their associated downstream signal and generate an associated upstream signal.

Abstract: According to the invention, various noise currents are added to the electrical data signal after the opto-electric conversion of an optical data signal, and an optimum decision threshold for the electrical data signal equipped with this noise current is determined for each noise current. Values for a median signal current and for a median noise current of the amplified spontaneous emission are subsequently determined from the value pairs of the optimum decision threshold and the added noise current in accordance with a computation rule that is based on a noise model, and the optimum signal-to-noise ratio is calculated from their quotient. The method may also be advantageously implemented by means of simple expansions of common receiver devices.

Abstract: An optical component contains a tunable laser. The tunable laser provides an optical local oscillator signal, and the tunable laser is directly modulated to provide a modulated optical data signal. In this manner we have optimization of the channel wavelength and obtain an optimized electrical and optical bandwidth utilization. Furthermore, a method for data processing is suggested.

Abstract: A method for data processing in an optical network includes providing at least one main wavelength and processing a subcarrier modulation for the at least one main wavelength, wherein a portion of the subcarrier modulated signal is suppressed. An optical network component and a communication system having such an optical network component are also provided.

Abstract: A method for data processing in an optical network includes providing several main wavelengths and processing a subcarrier modulation for the several main wavelengths. An optical network component and a communication system including such an optical network component are also provided.

Abstract: The invention relates to a method and a system for controlling a PMD compensator (2). For this purpose, a measuring signal (MS) is branched off from an already compensated optical data signal (ODSK) and supplied to a polarization adjuster (2). The output signal of the latter is supplied to an optical filter unit (61) and subdivided into two optical measuring signal components (OMK1, OMK2) having different polarizations. After a respective opto-electrical conversion, the spectra are compared with each other in an analysis and control unit (81) and the PMD compensator (2) is adjusted in such a manner that they are as identical as possible.

Abstract: A tilt correction pump laser is injected into an optical fiber in an opposite direction of the transmission direction of a wavelength multiplex signal and an optical isolator or filter is provided to block the tilt correction signal in order to restrict the effective fiber length for the tilt correction pump signal to enable a faster adjustment of the tilt.

Abstract: A subcarrier system generates a phase comparison signal in a transmitter and transmits the phase comparison signal together with an optical subcarrier multiplex signal in the same transmission channel of an optical network. A receiver measures a phase distortion between a phase reference signal and the received phase comparison signal for each modulation section of the received subcarrier symbols, calculating at least one correction value and correcting time jitters or phase impairments of all parallel received or regained subcarrier symbols as a function of the phase distortion of the received phase comparison signal. Time jitter/phase jitter can be compensated without high hardware expenses.

Abstract: A method and an optical network component for data processing in an optical network. A first signal and a second signal are influenced by a tunable element. The first signal is an incoming optical signal, and the second signal is a local oscillator signal generated by a laser. The laser has an optical gain element that is tuned by the tunable element. A communication system is provided with the optical network component.

Abstract: A method provides and/or controls an optical signal, wherein a control signal and at least one data signal are optically processed into a combined signal of substantially constant optical power. The level of the at least one data signal is substantially maintained within the combined signal. In addition, an according device is provided. Suitable for compensation of Raman tilt in WDM communication systems.

Abstract: In the signal quality detector (7, 8, 10), a 3R-regenerated electrical received signal (REDS) is correlated with a non-regenerated received signal (EDS). The result is a direct measure of the correlation between non-regenerated and regenerated received signals and can be used for controlling a PMD-compensator (3).

Abstract: A transmitter-side transmission signal for compensating disturbances caused by e transmission properties of an optical transmission system is provided. A high-bit-rate-binary signal is serially introduced into an N-level-shift register. A bit pattern whose bit number depends on the transmission system disturbance influence is removed from the shift register and introduced into comparators connected to comparative-value registers. The comparative-value registers include values received from a transmission function and from various binary-bit patterns. In the comparators, the binary-bit pattern introduced is converted into a binary combination which is introduced into a digital-analog transducer, which transmits a compensation signal, corresponding to a discrete value for the amplitude or phase of the transmission signal corresponding a desired signal form, to a modulator.

Abstract: The invention relates to an optical regenerator for a differential phase modulated data signal which comprises, in addition to a unit for bit-by-bit gauge leveling, a unit for the regeneration of the phase of individual symbols of the differential phase modulated data signal. After the bit-by-bit gauge leveling, the data signal that is preset in amplitude is divided into a first and a second data signal. Phase errors of individual signals are detected for the first data signal in a phase error detection unit, are transformed into a correction signal, and are conveyed to a phase error correction unit. The second data signal is corrected in the phase error correction unit, depending on the correction signal conveyed thereto in the phase of said data signal, in such a way that a differential phase modulated data signal, regenerated in amplitude and in phase, is delivered at the output of the correction unit.

Abstract: Method for reducing signal degradation in an optical polarisation-multiplex system. The modulated optical signals to be transmitted are synchronised or generated such that the phase difference for NRZ-modulated signals is at least approximately 0° and the phase difference for RZ-modulated signals is at least approximately 180°. They can also be achieved by means of different synchronising devices.

Abstract: According to the invention, various noise currents are added to the electrical data signal after the opto-electric conversion of an optical data signal, and an optimum decision threshold for the electrical data signal equipped with this noise current is determined for each noise current. Values for a median signal current and for a median noise current of the amplified spontaneous emission are subsequently determined from the value pairs of the optimum decision threshold and the added noise current in accordance with a computation rule that is based on a noise model, and the optimum signal-to-noise ratio is calculated from their quotient. The method may also be advantageously implemented by means of simple expansions of common receiver devices.

Abstract: An anti-pump laser (AL) is used in addition to a tilt correction pumplaser (KL) for Raman tilt control, said anti-pump laser injecting an anti-pump signal into a transmission fiber (FI) or a dispersion compensation fiber (DCF). The anti-pump laser (AL) has the function of reducing the pump energy of the control pump laser (KL) in the course of the fiber (FI, DCF), in order to restrict its effective length and to enable a faster adjustment of the tilt.