Abstract: The bidirectional dispersion compensator comprises at least one circulator (Z,Z1,Z2,Z4) and at least one filter-coupler element (F1, etc.). The optical signals (S1,S2) that are emitted in opposite directions are merged and sent to a compensation fiber (LK,LK1, etc.) together, are reflected at the ends of this fiber, and are forwarded in the respective directions of transmission as dispersion-compensated optical signals (SK1 and SK2).

Abstract: Chromatic dispersion in a high speed CS-RZ WDM transmission system is reduced by providing tailored “precompensation” for individual and/or groups of optical signals. Such precompensaiton is achieved by passing the optical signals through a dispersion compensating elements, such as dispersion compensating fiber, within an optical multiplexer, i.e., prior to multiplexing the signals onto a single optical fiber. Additional dispersion compensation can be performed in optical amplifiers and within an optical demultiplexer downstream from the optical multiplexer.

Abstract: The invention is the novel use of dispersion compensation in a long haul wavelength division multiplexed high capacity optical transport system which has very many channels packed extremely closely together, in order to greatly reduce the deleterious effects of four-wave mixing. Four-wave mixing is an exchange of energy between nominally independent channels, arising from the fundamental fibre non-linearity, which has the effect of degrading transmission quality. Conventional systems make use of fibre dispersion compensating modules to overcome the effects of fibre dispersion. In such systems, it has been discovered that the exact distribution of fibre dispersion along the optical link (the ‘dispersion map’) strongly influences the degree of four-wave mixing, and hence the degradation in transmission quality.

Abstract: The present invention relates to an optical fiber transmission line and the like comprising a structure for enabling repeating sections to become further longer. The optical fiber transmission line comprises first and second optical fibers successively disposed along the advancing direction of signal light, and an optical multiplexer for supplying Raman amplification pumping light to one of the first and second optical fibers. The first and second optical fibers are fusion-spliced to each other, whereas at least one of them has a core region substantially made of pure silica glass. The second optical fiber has an effective area smaller than that of the first optical fiber, and a chromatic dispersion and a length which are different from those of the first optical fiber. In particular, the respective lengths of the first and second optical fibers are appropriately regulated so as to effectively suppress nonlinear phenomena other than Raman amplification.

Abstract: The present invention is a method of processing an optical signal, including the steps of (a) inputting signal light into a first nonlinear optical medium to broaden the spectrum of the signal light through self phase modulation occurring in the first nonlinear optical medium, thereby obtaining first spectrally broadened light, (b) compensating for chromatic dispersion effected on the first spectrally broadened light obtained in the step (a), and (c) inputting the first spectrally broadened light processed by the step (b) into a second nonlinear optical medium to broaden the spectrum of the first spectrally broadened light through self phase modulation occurring in the second nonlinear optical medium, thereby obtaining second spectrally broadened light.

Abstract: A method and device is disclosed for dispersion compensation of an optical signal. By providing two filters having a sloped dispersion and opposite in sign over a wavelength band wherein one filter is tunable, a controllable amount of dispersion can be introduced to offset or compensate dispersion. Preferably one of the filters is a tunable periodic device in the form of a multi-cavity GT etalon. In a preferred embodiment of the filters can be designed to provide various controllable but different constant amounts of dispersion.

Abstract: An optical communication system and method of use thereof which uses dispersion compensators to intentionally create a dispersive condition at the output of subsequent inline optical amplifiers. The present invention reduces four-wave mixing and increases the allowable spacing between optical amplifiers, thus reducing the required number of amplifiers and dispersion compensators for a given length of optical fiber. In one embodiment, dispersion compensators and optical amplifiers are alternately spaced from one another along a length of an optical fiber such that the dispersion compensators render a dispersive condition at the amplifiers allowing each amplifier to be run at a higher power level. In another embodiment, the dispersion compensator is collocated with the amplifier, but is positioned between a pre-amp stage and a high power output stage to overcompensate both the slope and absolute dispersion of the fiber up to that point.

Abstract: The invention provides an optical communication system, an optical transmitting apparatus, an optical receiving apparatus, an optical communication method, and a storage medium, in which a large-capacity transmission can be performed at high speed and multiplexing efficiency can be improved. The optical communication system includes an optical transmitting apparatus and an optical receiving apparatus connected via a transmitting medium having anomalous dispersion characteristics. In this system, the optical transmitting apparatus converts a plurality of information signals output from a plurality of signal sources into light signals having amplitudes different according to the respective information signals to output the light signals LP, by providing an individual specified optical intensity capable of performing an optical soliton transmission.

Abstract: An in-cable monomode optical fiber has a step and ring index profile and, for a wavelength of 1,550 nm: an effective surface area greater than or equal to 60 &mgr;m2, a chromatic dispersion from 3 to 14 ps/(nm.km), a chromatic dispersion slope from 0 to 0.1 ps/(nm2.km), and a ratio between the effective surface area and the chromatic dispersion slope greater than 900 &mgr;m2.nm2.km/ps.

Abstract: A dispersion compensating optical fiber comprises a minimum wavelength at which an increase amount of an actual loss value with respect to a theoretical loss value is not less than 10 mdB/km in a use wavelength band and on a long wavelength side of the use wavelength band. The actual loss value is measured in a state that the fiber is looped around a bobbin. The minimum wavelength falls within a range of 1,565 to 1,700 nm. This dispersion compensating optical fiber is suitably used for an optical transmission line of a large-capacity high-speed WDM optical transmission system.