Optical system and method having low loss and non-linear effects

A light transmission signal device and method. The invention relates to a a first (16) and second (18) monomode fibre transmission line. The first optical fibre with a compensating; the negative compensating pressure of the operating wavelength of an 2.5ps/nm/k to 10ps/nm/k. The second (18) is first (16), and positive dispersion of the operating wavelength. The second positive dispersion compensation the first a compensating, so first and second opening compensating the is a. Compensating value of the first added with a matching box of a nonlinearity, the second containing with long hole, which is useful to reducing the transmission line the attenuation.