Segmented Optical Amplifier Using Out-of-Band Gain Clamping

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Solution Overview

Problem

Optical amplifiers in optical communication systems suffer from nonlinear penalties due to gain saturation, leading to distortion and degradation of transmission quality when output power exceeds a specific threshold.

Innovation Solution

The optical amplifier employs multiple gain media with gain clamping using light outside the communication band to reduce nonlinear penalties, improving saturated output power and reducing the need for external light sources.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If output power of the gain medium is increased to amplify the optical signal, then amplification capability is improved, but gain saturation effect occurs causing nonlinear penalty and signal distortion

Engineering Contradiction:
Improveamplification capabilityVSAvoidnonlinear penalty
Core Design Contradiction:
PowerVSObject-generated harmful factors

Solution Approach 1:

The patent divides the gain medium into multiple segments (first gain medium, second gain medium, third gain medium) with different functions. The first gain medium performs signal amplification, while the second and third gain media perform gain clamping using light outside the communication band. This segmentation allows high output power without gain saturation-induced distortion.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces gain clamping light outside the communication band as an intermediary to control the gain medium's saturation state. This light acts as a mediator that prevents harmful nonlinear effects while allowing useful signal amplification to proceed at high power levels.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Power

If gain clamping light outside the communication band is introduced to reduce nonlinear penalty, then saturated output power is improved, but device complexity increases due to additional light sources

Engineering Contradiction:
Improvesaturated output powerVSAvoiddevice complexity
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

The patent makes the gain medium serve multiple functions: it amplifies the communication band signal and simultaneously performs gain clamping using light outside the communication band. This multi-functionality eliminates the need for separate external light sources, reducing device complexity while maintaining high saturated output power.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The gain medium generates and uses its own gain clamping light from spontaneous emission outside the communication band, making the system self-sufficient. This self-service approach eliminates dependency on external light sources and reduces overall device complexity.

Inventive Principle:
Principle #25Self-service

3Device complexity

If light outside the communication band is discarded as in conventional systems, then device structure is simple, but utilization of light is low and external light sources are required

Engineering Contradiction:
Improvedevice structureVSAvoidlight utilization
Core Design Contradiction:
Device complexityVSLoss of energy

Solution Approach 1:

The patent converts the previously harmful or wasted light outside the communication band into a useful resource for gain clamping. By utilizing this light to control saturation effects, the system transforms a disadvantage into an advantage, improving light utilization while maintaining simple device structure.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The system uses its own spontaneously emitted light outside the communication band for gain clamping purposes, making the gain medium self-sufficient. This eliminates the need for external light sources and maximizes light utilization within the system.

Inventive Principle:
Principle #25Self-service

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach enhances the performance of the optical amplifier by increasing utilization of light outside the communication band, reducing nonlinear penalties, and minimizing the requirement for external light sources, thereby improving overall system performance.

Implementation Method 1

The first gain medium is configured to amplify the first optical signal, to obtain target light. In a process of amplifying the first optical signal through the first gain medium, the first gain medium performs gain clamping on the first optical signal based on the first gain clamping light

Methodology Applied
Scientific EffectStimulated emission:

Implementation Method 2

The second gain medium is configured to amplify the target light or the target light amplified through a target gain medium

Methodology Applied
Scientific EffectStimulated emission:

Implementation Method 3

The first multiplexer/demultiplexer is configured to separate the first gain clamping light from the target light amplified through the second gain medium

Methodology Applied
Scientific EffectWavelength division multiplexing:

Data Source

PatentEP4693773A1Optical amplifier and related device
Publication Date: 2026.02.11 HUAWEI TECH CO LTD
  • EP4693773A1 patent drawingFigure 1~3
  • EP4693773A1 patent drawingFigure 4~5
  • EP4693773A1 patent drawingFigure 6~7

AI summary

An optical amplifier and a related device are provided to reduce a nonlinear penalty of a gain medium. The optical amplifier includes a first gain medium, a second gain medium, a first multiplexer/demultiplexer, and a second multiplexer/demultiplexer. The second multiplexer/demultiplexer is configured to output, to the first gain medium in a coupling manner, a first optical signal and first gain clamping light output by the first multiplexer/demultiplexer. The first optical signal is an input optical signal of the optical amplifier, or is an optical signal obtained by amplifying the input optical signal of the optical amplifier. The first gain medium is configured to: amplify the first optical signal, and perform gain clamping on the first optical signal based on the first gain clamping light, to obtain target light. The second gain medium is configured to amplify the target light or the target light amplified through a target gain medium. The first multiplexer/demultiplexer is configured to separate the first gain clamping light from the target light amplified through the second gain medium.