US 7,002,734 B2 · Pre-amplifier gain setting method utilizing ASE light and WDM optical transmission apparatus employing the method

Abstract

A WDM optical transmission apparatus is disclosed utilizing ASE light. The WDM optical transmission apparatus includes a pre-amplifier having two control modes consisting of ALC mode in which the gain of an optical amplifier is controlled such that the total output of the optical amplifier is constant for a multiplexed wavelength number n, and of AGC mode which is a control mode maintaining constant the ratio of an optical input level to an optical output level for the multiplexed wavelength number n; and a post-amplifier having two control modes consisting of ASE mode in which the gain of the post-amplifier is set higher than that in the AGC mode and is set such that the output level of ASE light corresponds to the multiplexed wavelength number n, and of the AGC mode; wherein in the ASE mode, the gain of the pre-amplifier in the WDM optical transmission apparatus at the next node is set under an ALC control utilizing ASE light output from the post-amplifier.

Claims14

Dependent claims

A WDM optical transmission apparatus disposed at a node of a ring network or of an open ring network, comprising:

a pre-amplifier having two control modes consisting of ALC mode in which the gain of an optical amplifier is controlled such that the total output of the optical amplifier is constant for a multiplexed wavelength number n, and of AGC mode which is a control mode maintaining constant the ratio of an optical input level to an optical output level for the multiplexed wavelength number n;
and
a post-amplifier having two control modes consisting of ASE mode in which the gain of the post-amplifier is set higher than that in the AGC mode and is set such that the output level of ASE light corresponds to the multiplexed wavelength number n, and of the AGC mode;
wherein in the ASE mode, the gain of the pre-amplifier in the WDM optical transmission apparatus at the next node is set under an ALC control utilizing ASE light output from the post-amplifier.

1 more element

A method of setting the gain of a pre-amplifier of a WDM optical transmission apparatus having the pre-amplifier and a post-amplifier and placed at a node of a ring network or of an open ring network, the method comprising the steps of;

for the pre-amplifier, setting two control modes consisting of ALC mode in which the gain of an optical amplifier is controlled such that the total output of the optical amplifier is constant with respect to the multiplexing wavelength number n and of AGC mode that is a control mode for maintaining constant the ratio of an optical input level to an output optical level;
setting two control modes consisting of ASE mode in which the gain of the post-amplifier is set higher than that in the AGC mode and is set such that the output level of an ASE light corresponds to the multiplexing wavelength number n, and of AGC mode;
and
in the ASE mode, outputting the ASE light of the post-amplifier and setting the gain of the pre-amplifier in the WDM optical transmission apparatus at the next node under the ALC control utilizing the ASE light.

1 more element

Dependencies are inferred from the claim text.

Pre-amplifier gain setting method utilizing ASE light and WDM optical transmission apparatus employing the method

Life of this patent

Pre-amplifier gain setting method utilizing ASE light and WDM optical transmission apparatus employing the method

Life of this patent

Abstract

Claims14