US 2001/0024304 A1 · Optical transmission system and method

Abstract

Signal wavelengths λ1, λ2, λ3 of signal light components multiplexed at signal multiplexing sections 31, 41, 51 of multiplexing stations 3, 4, 5 installed on the input end side of an EDFA 2 on an optical transmission line 1 are set such that the wavelength-dependent noise figure of EDFA 2 successively decreases from the signal wavelength λ1 multiplexed at the signal multiplexing section 31 closest to the input end of EDFA 2 to λ2 and λ3. On the other hand, the transmission length of individual signal light component before being fed into the EDFA 2 is the shortest in the signal light component at λ1 and successively increases at λ2 and λ3. Thus, the order of magnitude of input signal light power is the same as the order of highness of noise figure in EDFA 2, whereby fluctuations in S/N ratio in the resulting amplified light are reduced.

Claims18

Dependent claims

An optical transmission system comprising:

an optical transmission line through which a plurality of signal light components having wavelengths different from each other included in a predetermined wavelength band are transmitted;
an optical amplifier, installed on said optical transmission line, having a wavelength-dependent noise figure;
and
a plurality of multiplexing stations each constituted by a signal multiplexing section installed on said optical transmission line connected to an input end side of said optical amplifier, and at least one signal light outputting means for outputting a signal light component multiplexed at said signal multiplexing section;
wherein, between two of said multiplexing stations adjacent each other, said signal light outputting means of said multiplexing station disposed upstream in a signal light propagating direction outputs a signal light component having a signal wavelength set so as to yield a noise figure lower than that of the signal wavelength of a signal light component outputted from said signal light outputting means of said multiplexing station disposed downstream.

2 more elements

An optical transmission system comprising:

an optical transmission line through which a plurality of signal light components having wavelengths different from each other included in a predetermined wavelength band are transmitted;
a plurality of optical amplifiers, installed on said optical transmission line, each having a wavelength-dependent noise figure;
a first multiplexing station having a first signal multiplexing section installed upstream said plurality of optical amplifiers in a signal light propagating direction, and first signal light outputting means for outputting a first signal light component multiplexed at said first signal multiplexing section;
a second multiplexing station having a second signal multiplexing section installed upstream said plurality of optical amplifiers but downstream said first signal multiplexing section, and second signal light outputting means for outputting a second signal light component multiplexed at said second signal multiplexing section;
and
a receiving station, installed downstream said plurality of optical amplifiers, for receiving said first signal light component having a first signal wavelength multiplexed at said first signal multiplexing section and said second signal light component having a second signal wavelength multiplexed at said second signal multiplexing section;
wherein said first signal light outputting means outputs said first signal light component having said first signal wavelength set such that said noise figure between said first signal multiplexing section and said receiving station is lower than that of said second signal wavelength.

4 more elements

Dependencies are inferred from the claim text.

Optical transmission system and method

Life of this patent

Optical transmission system and method

Life of this patent

Abstract

Claims18