Optical transmission system comprising dispersion management system
An optical transmission system having optical fibres having chromatic dispersion of alternate sign arranged in an optical path in accordance with a dispersion map appropriate for the transmission of dispersion managed solitons at a wavelength λ c . The transmission system has a transmission station and a receiver station connected to the optical path. The transmission station launches at least a first optical pulse of wavelength λ1 which is different from λc on the optical path. At least one wavelength conversion device such as a phase conjugation device located along the optical path alters the wavelength of the first pulse of wavelength λ1 in such a way as to obtain a second pulse of wavelength λ2, such that λ2 is on the opposite side from λ1 with respect to λc.
1 - 15 . (Canceled)
16 . A method for the transmission of optical pulses along an optical path (OL) comprising optical fibres having dispersion of alternating sign arranged in accordance with a dispersion map suitable for the transmission of DM solitons at a wavelength λ c comprising the steps of:
(a) launching at least a first optical pulse RZ having a first wavelength λ 1 which is different from λ c on a first portion of said optical path;
(b) at the end of said first portion of said optical path, modifying the wavelength of at least said first optical pulse in such a way as to obtain a second optical pulse RZ having a second wavelength λ 2 , such that λ 2 is on the opposite side from λ 1 with respect to Ac; and
(c) launching said second optical pulse on a second portion of said optical path.
17 . The method according to claim 16 , wherein said step of modifying the wavelength is carried out in such a way that (λ 1 +λ 2 )/2 is substantially equal to λ c .
18 . The method according to claim 16 or 17 , wherein said step of modifying the wavelength comprises the step of inverting the spectrum of said first optical pulse RZ.
19 . The method according to claim 18 , wherein said step of inverting the spectrum is performed in a chirp cancellation portion along said optical path.
20 . The method according to claim 16 , further comprising the step of amplifying said first optical pulse before the step of modifying the wavelength of said first optical pulse.
21 . An optical transmission system comprising optical fibres having dispersion of alternating sign arranged in an optical path (OL) in accordance with a dispersion map suitable for the transmission of DM solitons at a wavelength Ac, comprising:
a transmission station and a receiver station connected to said optical path, said transmission station being capable of launching on said optical path at least a first optical pulse RZ at a wavelength λ 1 which is different from λ c ; and
at least one wavelength conversion device located along said optical path, capable of modifying the wavelength of at least said first pulse having a wavelength λ 1 in such a way as to obtain a second pulse having a wavelength λ 2 , such that λ 2 is on the opposite side of λ 1 with respect to λ c .
22 . The optical transmission system according to claim 21 , wherein said second wavelength λ 2 is such that (λ 1 +λ 2 )/2 is substantially equal to λ c .
23 . The optical transmission system according to claim 21 , wherein said conversion device is a phase conjugation device.
24 . The optical transmission system according to claim 23 , wherein said phase conjugation device is located along said optical path in a chirp cancellation portion.
25 . The optical transmission system according to claim 21 , wherein said optical path comprises at least one amplifier.
26 . The optical transmission system according to claim 25 , wherein said conversion device is located at an amplifier.
27 . The optical transmission system according to claim 21 , wherein said optical fibres having dispersion of alternate sign have a dispersion which is greater than or equal to 1 ps/(nm km) in absolute value.
28 . The optical transmission system according to claim 21 , wherein said dispersion map comprises spans having at least three segments of optical fibre.
29 . The optical transmission system according to claim 21 , wherein said optical path has a slope of the average dispersion of less than 0.08 ps/(nm 2 km).
30 . The optical transmission system according to claim 21 , wherein said first pulse has a normal average dispersion in said first portion of optical path.