Patent ID: 6538788
Filing Date: 2003-03-25
Classification: H04B

Abstract:
A method for reducing noise in a long distance optical telecommunications system, comprising:transmitting an optical signal on an optical fiber telecommunications line that comprises optical amplifiers and has a substantially compensated dispersion; receiving from said line a noisy optical signal that comprises said transmitted optical signal and an optical noise signal; generating an electronic signal correlated with said noisy optical signal, said electronic signal being associated with a quality parameter (Q) that depends on said optical noise signal and distortion of said optical signal; and applying to said optical signal a nonlinear phase-shift ei&psgr; associated with a variation of phase &psgr; greater than 0.5 radiants, and a normal dispersion &bgr;2,NORMÂ·L, said nonlinear phase-shift and said normal dispersion being operatively selected to increase said quality parameter by at least 1 dB.