Abstract: A technique is provided for determining an optical transmission system description. The technique includes determining a dispersion map of the optical transmission system, placing a set of discrete cumulative dispersions onto the dispersion map, and defining a plurality of sequential system segments of the optical transmission system. Each system segment has an input point that corresponds to a point in the optical transmission system where the input cumulative dispersion matches a cumulative dispersion of the set of discrete cumulative dispersions. For each system segment, an input power of the system segment and a local dispersion value of the system segment is determined. Also, for each system segment, a sequence number of the system segments is stored. Furthermore, for each system segment, the input power and the local dispersion value determined in relation with the input cumulative dispersion of the system segment in a data repository is stored.

Abstract: A technique is provided for producing a quality of transmission estimator for optical transmissions. The technique includes defining a local dispersion value, defining a dispersion increment, and performing a propagation calculation of an optical signal along an elementary section. The elementary section is a propagation medium characterized by the local dispersion value. The elementary section length may correspond to the dispersion increment. The optical signal, which is incoming in the elementary section, is previously affected by a cumulative dispersion value equal to an integer number of the dispersion increment. For each elementary section, a variance of noise is determined, the noise representing a distortion due to Kerr nonlinear field contributions in the elementary section. For each couple of elementary sections, a covariance of noise is determined between the couple of elementary sections. The variances and covariances may be stored in a look-up table of a data repository.

Abstract: A technique is provided for determining an optical transmission system description. The technique includes determining a dispersion map of the optical transmission system, placing a set of discrete cumulative dispersions onto the dispersion map, and defining a plurality of sequential system segments of the optical transmission system. Each system segment has an input point that corresponds to a point in the optical transmission system where the input cumulative dispersion matches a cumulative dispersion of the set of discrete cumulative dispersions. For each system segment, an input power of the system segment and a local dispersion value of the system segment is determined. Also, for each system segment, a sequence number of the system segments is stored. Furthermore, for each system segment, the input power and the local dispersion value determined in relation with the input cumulative dispersion of the system segment in a data repository is stored.

Abstract: A technique is provided for modulating light in a telecommunication network. The technique includes modulating light with a first intensity modulator and modulating light with a second intensity modulator. The first intensity modulator and the second intensity modulator are applied a mutual angular phase shift. The mutual angular phase shift is non-orthogonal and non-PI/2-dividable.

Abstract: An exemplary method is provided for determining a maximum transmission distance for an optical link that has heterogeneous types of optical fiber segments. The method includes retrieving from a database a maximum transmission reach value for each type of optical fiber present in the optical link. A length of each type of the optical fiber to reach a distance is computed, where, for each type of the optical fiber present in the optical link, segments are summed from a starting point to the distance to determine the length of each type of the optical fiber along the optical link. The length for each type of the optical fiber in the optical link is normalized by multiplying the length of each type of the optical fiber by a weight chosen as a function of the maximum transmission reach value for each type of said optical fiber.

Abstract: A method, for determining a maximum transmission distance (Dmax) for an optical link comprising heterogeneous types of optical fibre segments, comprising: for a type of optical fibre present in said optical link: retrieve a maximum transmission reach (Mi), determine along said optical link, a length (xi) of optical fibre of said type, to reach a distance (D), normalize said length (xi), by multiplying said length (xi) by a weight (?i) function of said maximum transmission reach (Mi), sum said normalized lengths for a plurality of types of optical fibre, determine the maximum transmission distance (Dmax) of the optical link as the distance (D) for which said sum equals a given threshold.

Abstract: A method of operating a WDM transmission system with at least one transmitter and at least one receiver connected by means of a dispersive transmission line.

Abstract: A multimode fiber having an index profile such that, for a propagation mode other than the fundamental mode and at a wavelength of 1550 nm, the fiber presents a positive chromatic dispersion greater than or equal to 50 ps/run/km, a positive chromatic dispersion slope and a figure of merit (FOM) greater than or equal to 200 ps/run/dB.

Abstract: A method of operating a WDM transmission system (1) with at least one transmitter (4) and at least one receiver (6) connected by means of a dispersive transmission line (8).

Abstract: A network element (5) for use in a wavelength division multiplex (WDM) optical transmission system (1). The WDM optical transmission system (1) comprises at least one demultiplexing means (5c) adapted to demultiplex a received WDM signal into constituent wavelength channels carrying tributary signals with at least a first and at least a second data rate (DR1, DR2). The optical transmission system (1) further comprises at least one first dispersion compensating module (5e) connected with the demultiplexing means for receiving constituent wavelength channels carrying tributary signals having said first data rate (DR1). Furthermore, the optical transmission system comprises at least one bypass bypassing the first dispersion compensating module and connected with the demultiplexing means for receiving constituent wavelength channels carrying tributary signals having said second data rate (DR2).

Abstract: A multimode fiber having an index profile such that, for a propagation mode other than the fundamental mode and at a wavelength of 1550 nm, the fiber presents a positive chromatic dispersion greater than or equal to 50 ps/run/km, a positive chromatic dispersion slope and a figure of merit (FOM) greater than or equal to 200 ps/run/dB.

Abstract: The present invention relates to a method of determining the performance of a heterogeneous optical transmission system, which preferably comprises wavelength division multiplexing (WDM), wherein said heterogeneous optical transmission system comprises a plurality of preferably homogenous optical transmission subsystems (i), characterized by determining a criterion (?) for said performance of the heterogeneous optical transmission system depending on a weighted combination of performance criteria (?(i)) of said optical transmission subsystems (i). The present invention further relates to a system for determining the performance of a heterogeneous optical transmission system comprising wavelength division multiplexing (WDM), wherein said heterogeneous optical transmission system comprises a plurality of preferably homogenous optical transmission subsystems (i).

Abstract: It is proposed a method for processing optical signals to be transmitted through a succession of transmission lines spans made out of DSF and a system architecture allowing the implementation of such a method for compensating dispersion occurring at the transmission path without suffering too much from any cross-phase modulation. This is achieved by the use of a system architecture comprising a succession of transmission lines spans made out of dispersion shifted fibers DSF with in-between a stage made alternately by a single mode fiber SMF or a dispersion compensating fiber DCF. Both DSF and SMF have dispersion of same sign. In another embodiment of the system architecture, the used DSF and SMF have also both dispersion slope of same sign. In such a way, it is possible to limit the impact of the XPM by not compensating the dispersion and possibly the dispersion slope at each span.

Abstract: The present invention relates to a method of operating an optical amplifier (1a), in particular an erbium doped fiber amplifier (EDFA) or a Raman amplifier, an output signal of which is supplied to an optical fiber (2), characterized by determining a span loss of said optical fiber (2) and by controlling an output power (P_out) of said optical amplifier (1a) depending on said span loss. The present invention further refers to an optical amplifier (1a), in particular an erbium doped fiber amplifier (EDFA) or a Raman amplifier.