L-band optical fiber amplifier with pumping balance

Patent metadata

Field	Value
Publication number	US-11245242-B2
Application number	US-201816230305-A
Country	US
Kind code	B2
Filing date	Dec 21, 2018
Priority date	Nov 13, 2018
Publication date	Feb 8, 2022
Grant date	Feb 8, 2022

Abstract

The present invention relates to the field of optical communication, and particularly to a balanced pumping L-band optical fiber amplifier comprising a first erbium-doped optical fiber, a second erbium-doped optical fiber, an absorbing erbium-doped optical fiber and at least two pumping lasers, the first erbium-doped optical fiber, the second erbium-doped optical fiber and the absorbing erbium-doped optical fiber being sequentially arranged in this order, and the at least two pumping lasers providing pumping light; wherein the first erbium-doped optical fiber and the second erbium-doped optical fiber both are injected with forward pumping light and backward pumping light, and the absorbing erbium-doped fiber is arranged downstream of the second erbium-doped optical fiber to absorb amplified spontaneous emission (ASE) generated in the amplifier. In the present invention, bidirectional pumping 1s applied in the first and last erbium-doped fibers in the optical path, and an erbium-doped optical fiber that has no pumping injection is added to absorb the ASE. Thus, the pumping conversion efficiency is greatly improved, the nonlinear four-wave mixing effect is reduced, and the problem that the L-band optical fiber amplifier has a high noise when utilizing the backward pumping 1s solved. Meanwhile, the noise figure and the manufacturing cost of the amplifier are reduced.

First claim

The invention claimed is:

1. A balanced pumping L-band optical fiber amplifier, characterized in comprising a first erbium-doped optical fiber ( 1 - 1 ), a second erbium-doped optical fiber ( 1 - 2 ), an absorbing erbium-doped optical fiber ( 1 - 3 ) and at least two pumping lasers, the first erbium-doped optical fiber ( 1 - 1 ), the second erbium-doped optical fiber ( 1 - 2 ) and the absorbing erbium-doped optical fiber ( 1 - 3 ) being sequentially arranged in this order, and the at least two pumping lasers providing pumping light;
wherein the first erbium-doped optical fiber ( 1 - 1 ) is injected with forward pumping light and backward pumping light by the at least two pumping lasers, the second erbium-doped optical fiber ( 1 - 2 ) is injected with forward pumping light and backward pumping light by the at least two pumping lasers, and the absorbing erbium-doped fiber ( 1 - 3 ) is arranged downstream of the second erbium-doped optical fiber ( 1 - 2 ) to absorb amplified spontaneous emission (ASE) generated in the amplifier;
a first isolator ( 2 - 1 ), a first combiner ( 3 - 1 ), a second combiner ( 3 - 2 ), a third combiner ( 3 - 3 ), a fourth combiner ( 3 - 4 ), a second isolator ( 2 - 2 ) and a third isolator ( 2 - 3 ) connected sequentially in this order;
wherein the first erbium-doped optical fiber ( 1 - 1 ) is connected between a common end of the first combiner ( 3 - 1 ) and a common end of the second combiner ( 3 - 2 ), the second erbium-doped optical fiber ( 1 - 2 ) is connected between a common end of the third combiner ( 3 - 3 ) and a common end of the fourth combiner ( 3 - 4 ), and the absorbing erbium-doped optical fiber ( 1 - 3 ) is connected between the second isolator ( 2 - 2 ) and the third isolator ( 2 - 3 );
wherein the at least two pumping lasers comprise a first pumping laser ( 4 - 1 ) and a second pumping laser ( 4 - 2 ), and the optical fiber amplifier further comprises a first pumping beam splitter ( 5 - 1 ) and a second pumping beam splitter ( 5 - 2 );
wherein the first pumping laser ( 4 - 1 ) is connected with a common end of the first pumping beam splitter ( 5 - 1 ), a first splitting port of the first pumping beam splitter ( 5 - 1 ) is connected with a pumping end of the first combiner ( 3 - 1 ), and a second splitting port of the first pumping beam splitter ( 5 - 1 ) is connected with a pumping end of the third combiner ( 3 - 3 ), so that the first pumping laser ( 4 - 1 ) injects the forward pumping light into the first erbium-doped optical fiber ( 1 - 1 ) and the second erbium-doped optical fiber ( 1 - 2 ) in the splitting pumping mode; and
the second pumping laser ( 4 - 2 ) is connected with a common end of the second pumping beam splitter ( 5 - 2 ), a first splitting port of the second pumping beam splitter ( 5 - 2 ) is connected with a pumping end of the fourth combiner ( 3 - 4 ), and a second splitting port of the second pumping beam splitter ( 5 - 2 ) is connected with a pumping end of the second combiner ( 3 - 2 ), so that the second pumping laser ( 4 - 2 ) injects the backward pumping light into the second erbium-doped optical fiber ( 1 - 2 ) and the first erbium-doped optical fiber ( 1 - 1 ) in the splitting pumping mode.

2. The balanced pumping L-band optical fiber amplifier of claim 1 , characterized in that each pumping laser adopts an independent pumping mode or a splitting pumping mode to provide the pumping light for the erbium-doped optical fibers that need to be injected with the pumping light.

3. The balanced pumping L-band optical fiber amplifier of claim 1 , characterized in further comprising a gain flatten filter ( 6 ) connected between a signal end of the second combiner ( 3 - 2 ) and a signal end of the third combiner ( 3 - 3 ), the gain flatten filter ( 6 ) itself including an integrated isolator.

4. The balanced pumping L-band optical fiber amplifier of claim 3 , characterized in that between the second combiner ( 3 - 2 ) and the gain flatten filter ( 6 ) are further provided a fourth isolator ( 2 - 4 ), a variable optical attenuator ( 7 ), a fifth combiner ( 3 - 5 ) and a third erbium-doped optical fiber ( 1 - 4 ) sequentially connected in this order, and the third erbium-doped optical fiber ( 1 - 4 ) is connected with a common end of the fifth combiner ( 3 - 5 ).

5. The balanced pumping L-band optical fiber amplifier of claim 4 , characterized in that the at least two pumping lasers comprise a first pumping laser ( 4 - 1 ), a second pumping laser ( 4 - 2 ) and a third pumping laser ( 4 - 3 ), and the optical fiber amplifier further comprises a first pumping beam splitter ( 5 - 1 ) and a second pumping beam splitter ( 5 - 2 );
wherein the first pumping laser ( 4 - 1 ) is connected with a common end of the first pumping beam splitter ( 5 - 1 ), a first splitting port of the first pumping beam splitter ( 5 - 1 ) is connected with a pumping end of the first combiner ( 3 - 1 ), and a second splitting port of the first pumping beam splitter ( 5 - 1 ) is connected with a pumping end of the third combiner ( 3 - 3 ), so that the first pumping laser ( 4 - 1 ) injects the forward pumping light into the first erbium-doped optical fiber ( 1 - 1 ) and the second erbium-doped optical fiber ( 1 - 2 ) in the splitting pumping mode;
the second pumping laser ( 4 - 2 ) is connected with a common end of the second pumping beam splitter ( 5 - 2 ), a first splitting port of the second pumping beam splitter ( 5 - 2 ) is connected with a pumping end of the fourth combiner ( 3 - 4 ), and a second splitting port of the second pumping beam splitter ( 5 - 2 ) is connected with a pumping end of the second combiner ( 3 - 2 ), so that the second pumping laser ( 4 - 2 ) injects the backward pumping light into the second erbium-doped optical fiber ( 1 - 2 ) and the first erbium-doped optical fiber ( 1 - 1 ) in the splitting pumping mode;
the third pumping laser ( 4 - 3 ) is connected with a pumping end of the fifth combiner ( 3 - 5 ), so that the third pumping laser ( 4 - 3 ) injects the forward pumping light into the third erbium- doped optical fiber ( 1 - 4 ) in the independent pumping mode.

6. The balanced pumping L-band optical fiber amplifier of claim 4 , characterized in that the at least two pumping lasers comprise a first pumping laser ( 4 - 1 ), a second pumping laser ( 4 - 2 ) and a third pumping laser ( 4 - 3 ), and the optical fiber amplifier further comprises a second pumping beam splitter ( 5 - 2 ) and a third pumping beam splitter ( 5 - 3 );
wherein the first pumping laser ( 4 - 1 ) is connected with a pumping end of the first combiner ( 3 - 1 ), so that the first pumping laser ( 4 - 1 ) injects the forward pumping light into the first erbium-doped optical fiber ( 1 - 1 ) in the independent pumping mode;
the second pumping laser ( 4 - 2 ) is connected with a common end of the second pumping beam splitter ( 5 - 2 ), a first splitting port of the second pumping beam splitter ( 5 - 2 ) is connected with a pumping end of the fourth combiner ( 3 - 4 ), and a second splitting port of the second pumping beam splitter ( 5 - 2 ) is connected with a pumping end of the second combiner ( 3 - 2 ), so that the second pumping laser ( 4 - 2 ) injects the backward pumping light into the second erbium-doped optical fiber ( 1 - 2 ) and the first erbium-doped optical fiber ( 1 - 1 ) in the splitting pumping mode;
the third pumping laser ( 4 - 3 ) is connected with a common end of the third pumping beam splitter ( 5 - 3 ), the first splitting port of the third pumping beam splitter ( 5 - 3 ) is connected with a pumping end of the fifth combiner ( 3 - 5 ), and a second splitting port of the third pumping beam splitter ( 5 - 3 ) is connected with a pumping end of the third combiner ( 3 - 3 ), so that the third pumping laser ( 4 - 3 ) injects the forward pumping light into the third erbium-do

Assignees

• Accelink Tech Co Ltd

Inventors

• Fu Chengpeng
• Yu Zhenyu
• Liu Qing
• Le Menghui
• Yu Chunping

Classifications

• H01S3/094061

  Shared pump, i.e. pump light of a single pump source is used to pump plural gain media in parallel · CPC title

• H01S2301/02

  ASE (amplified spontaneous emission), noise; Reduction thereof · CPC title

• H01S3/0677 Primary

  L-band amplifiers, i.e. amplification in the range of about 1560 nm to 1610 nm · CPC title

• H01S3/094011

  with bidirectional pumping, i.e. with injection of the pump light from both two ends of the fibre · CPC title

• H01S3/094096

  Multi-wavelength pumping · CPC title