JPH1155183A5

JPH1155183A5 -

Info

Publication number: JPH1155183A5
Application number: JP1998187139A
Authority: JP
Filing date: 1998-07-02
Publication date: 2005-05-19
Anticipated expiration: 2017-08-06

Claims

An optical transmission device that amplifies an optical signal received from an optical transmission line,
a first pumping light source that outputs first pumping light used to amplify an optical signal;
a first doped fiber that amplifies an optical signal received from the optical transmission line using the first pumping light;
a second pumping light source that outputs second pumping light used to amplify the optical signal;
a second doped fiber that amplifies the optical signal output from the first doped fiber using the second pumping light;
a third pumping light source that outputs third pumping light used to amplify an optical signal;
an optical transmission device comprising a third doped fiber for amplifying the optical signal output from the second doped fiber using the third pumping light;

2. The optical transmission device according to claim 1,
An optical transmission device characterized in that the amplification gain of the first doped fiber is in the range of 5 dB to 15 dB.

3. The optical transmission device according to claim 2,
The optical transmission device according to claim 1, wherein the first pumping light source outputs the first pumping light so that the intensity of the first pumping light is constant.

3. The optical transmission device according to claim 2,
the amplification gain of the second doped fiber is set to be larger than the amplification gain of the first doped fiber;
An optical transmission device characterized in that the amplification gain of the third doped fiber is set to be the same as or greater than the amplification gain of the first doped fiber, and smaller than the amplification gain of the second doped fiber.

3. The optical transmission device according to claim 2,
an optical transmission device comprising: a dispersion compensator disposed between the second doped fiber and the third doped fiber;

6. The optical transmission device according to claim 5,
a first optical isolator disposed between the first doped fiber and the second doped fiber;
an optical transmission device further comprising a second optical isolator disposed after the third doped fiber;

3. The optical transmission device according to claim 2,
a first photodetector for detecting the power of a portion of the optical signal before it is input to the first doped fiber;
an optical transmission device further comprising a control unit that compares an output of a portion of the optical signal detected by the first photodetector with a predetermined value, and controls the third pumping light source in accordance with a result of the comparison to adjust the intensity of the third pumping light.

8. The optical transmission device according to claim 7,
a second photodetector for detecting the output of a portion of the optical signal output from the third doped fiber;
The control unit adjusts the intensity of the third excitation light by controlling the third excitation light source so that the output of a portion of the optical signal detected by the second photodetector approaches a predetermined value.