Optical amplifier and gain adjustment method for optical amplifier

Patent metadata

Field	Value
Publication number	US-12567714-B2
Application number	US-202217573132-A
Country	US
Kind code	B2
Filing date	Jan 11, 2022
Priority date	Sep 27, 2019
Publication date	Mar 3, 2026
Grant date	Mar 3, 2026

Abstract

This application discloses an optical amplifier including a Raman fiber amplifier (RFA), a dynamic gain equalizer (DGE), a filter, an erbium-doped fiber amplifier (EDFA), an RFA gain controller, an EDFA gain controller, and an optical amplifier controller. The optical amplifier controller is configured to provide instructions to and receive feedback from the RFA and EDFA gain controllers. The RFA and the EDFA are configured to amplify an optical signal. The RFA gain controller is configured to control the RFA to adjust a gain. The EDFA gain controller is configured to control the EDFA to adjust a gain. The DGE adjusts insertion loss. The filter is configured to filter an amplified spontaneous emission signal produced in an optical amplification process of the RFA.

First claim

What is claimed is:

1 . An optical amplifier, comprising a Raman fiber amplifier (RFA), a dynamic gain equalizer (DGE), a filter, a first erbium-doped fiber amplifier (EDFA), an RFA gain controller, a first EDFA gain controller, and an optical amplifier controller, wherein
the RFA gain controller is connected to the RFA, the RFA gain controller is further connected to the filter, and the filter is connected to an output terminal of the RFA; the first EDFA gain controller is connected to the first EDFA; the optical amplifier controller is connected to the RFA gain controller, and the optical amplifier controller is further connected to the first EDFA gain controller; and the RFA is connected to the DGE, and the DGE is further connected to the first EDFA; the optical amplifier controller is configured to send a first instruction to the RFA gain controller, send a second instruction to the first EDFA gain controller, and send a DGE control instruction to the DGE; the RFA and the first EDFA are configured to amplify an optical signal, and the RFA gain controller is configured to control the RFA to adjust a gain according to the first instruction; the first EDFA gain controller is configured to control the first EDFA to adjust a gain according to the second instruction; and the DGE adjusts an insertion loss according to the DGE control instruction; and the filter is configured to filter an amplified spontaneous emission (ASE) signal produced in an optical amplification process of the RFA; wherein the optical amplifier controller determines an on-off gain of the RFA based on the ASE signal, wherein the on-off gain is a ratio of an output signal power with a pump of the RFA turned on to an output signal power with the pump turned off.

2 . The optical amplifier according to claim 1 , wherein the RFA gain controller being configured to control the RFA to adjust a gain according to the first instruction sent by the optical amplifier controller comprises:
receiving, by the RFA gain controller, the first instruction sent by the optical amplifier controller; and sending, by the RFA gain controller, a first pump control signal to the RFA according to the first instruction, so that the RFA adjusts a pump current based on the first pump control signal.

3 . The optical amplifier according to claim 1 , wherein the first EDFA gain controller being configured to control the first EDFA to adjust a gain according to the second instruction sent by the optical amplifier controller comprises:
receiving, by the first EDFA gain controller, the second instruction sent by the optical amplifier controller; and sending, by the first EDFA gain controller, a second pump control signal to the first EDFA according to the second instruction, so that the first EDFA adjusts a pump current based on the second pump control signal.

4 . The optical amplifier according to claim 1 , wherein the optical amplifier further comprises a second EDFA and a second EDFA gain controller, wherein
the second EDFA is connected between the RFA and the DGE, or the second EDFA is connected between the DGE and the first EDFA; and the second EDFA is connected to the second EDFA gain controller, and the second EDFA gain controller controls the second EDFA to adjust a gain, according to a fourth instruction sent by the optical amplifier controller.

5 . The optical amplifier according to claim 4 , wherein the second EDFA gain controller being configured to control the second EDFA to adjust a gain, according to a fourth instruction sent by the optical amplifier controller comprises:
receiving, by the second EDFA gain controller, the fourth instruction sent by the optical amplifier controller; and sending, by the second EDFA gain controller, a third pump control signal to the second EDFA according to the fourth instruction, so that the second EDFA adjusts a pump current based on the third pump control signal.

6 . The optical amplifier according to claim 1 , wherein the optical amplifier further comprises a gain flattening filter (GFF), and the GFF is configured to narrow an adjustment range of the insertion loss of the DGE.

7 . The optical amplifier according to claim 1 , wherein the RFA gain controller is further configured to send a first feedback message to the optical amplifier controller, and the first feedback message comprises an actual gain value of the RFA; the first EDFA gain controller is further configured to send a second feedback message to the optical amplifier controller, and the second feedback message comprises an actual gain value of the first EDFA.

8 . The optical amplifier according to claim 7 , wherein the optical amplifier controller obtains an insertion loss value of the DGE based on the actual gain value of the RFA and the actual gain value of the first EDFA, and the insertion loss value of the DGE is a value obtained by subtracting a target gain value of the optical amplifier from a sum of the actual gain value of the RFA and the actual gain value of the first EDFA.

9 . A gain adjustment method for an optical amplifier, wherein the method is applied to the optical amplifier according to claim 1 , and the method comprises:
determining a target gain value of the optical amplifier; adjusting an actual gain value of an RFA or an EDFA, and when a sum of the actual gain value of the RFA and the actual gain value of the EDFA is greater than the target gain value of the optical amplifier, determining an actual insertion loss value of the DGE; and sending a DGE control instruction to the DGE to adjust the insertion loss so that the insertion loss of the DGE reaches the determined actual insertion loss value of the DGE.

10 . The gain adjustment method according to claim 9 , wherein the actual insertion loss value of the DGE is obtained by subtracting the target gain value of the optical amplifier from a sum of the actual gain value of the RFA and the actual gain value of the EDFA.

11 . The gain adjustment method according to claim 9 , wherein the adjusting an actual gain value of an RFA or an EDFA comprises:
sending, by the optical amplifier controller, a first instruction to the RFA gain controller, or sending a second instruction to the EDFA gain controller; generating, according to the first instruction, a first pump control signal to adjust the actual gain value of the RFA; or generating, according to the second instruction, a second pump control signal to adjust the actual gain value of the EDFA.

12 . A memory configured to store a computer-executable instruction that, when executed by a processor, causes the processor to perform:
sending a first or a second control instruction to adjust a pump current of a RFA or a EDFA respectively; receiving a first feedback message and a second feedback message, wherein the first feedback message comprises an actual gain value of the RFA, and the second feedback message comprises an actual gain value of the EDFA; determining an actual insertion loss value of a DGE based on the actual gain value of the RFA and the actual gain value of the EDFA; and sending a DGE control instruction to control the insertion loss of the DGE, so that insertion loss of the DGE reaches the determined actual insertion loss value of the DGE; wherein the determining an actual insertion loss value of a DGE based on the actual gain value of the RFA and the actual gain value of the EDFA comprises:
determining that the sum of the actual gain value of the RFA and the actual gain value of the EDFA is greater than the target gain value of the optical amplifier;
subtracting the target gain value of the optical amplifier from the sum of the actual gain value of the RFA and

Assignees

• Huawei Tech Co Ltd

Inventors

• Jiang Hengyun

Classifications

• H01S2301/04

  Gain spectral shaping, flattening · CPC title

• H01S3/302

  in an optical fibre · CPC title

• H01S3/1608

  erbium · CPC title

• H01S3/10023

  by functional association of additional optical elements, e.g. filters, gratings, reflectors · CPC title

• H01S3/10015

  by monitoring or controlling, e.g. attenuating, the input signal · CPC title