Multi-core Optical Fiber Gain Deviation Control

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Solution Overview

Problem

In multi-core optical fiber amplifiers, deviations in amplification gain across core portions lead to inconsistent signal light quality due to variations in rare-earth metal doping and pumping light power, affecting the transmission capacity and reliability of Space Division Multiplexing communication systems.

Innovation Solution

A multi-core optical amplifying fiber device and amplifier that connects core portions in a specific configuration to minimize amplification gain deviations, using a connection method such as rotation or optical fiber bundles to equalize gain coefficients across the cores, thereby stabilizing the amplification process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If multi-core optical amplifying fiber is used for Space Division Multiplexing communication, then transmission capacity is increased, but amplification gain deviation occurs across core portions due to variations in rare-earth metal doping and pumping light power

Engineering Contradiction:
Improvetransmission capacityVSAvoidamplification gain consistency
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent changes the physical configuration parameter of the multi-core optical amplifying fiber by rotating the core portions around the cladding axis. This rotation transforms the spatial arrangement of cores relative to the pumping light input, thereby adjusting the distribution of pumping light power across different core portions and compensating for doping variations to achieve uniform amplification gain.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces asymmetric rotation angles for different core portions around the cladding axis. By setting specific rotation angles (e.g., 0°, 60°, 120°, 180°, 240°, 300° for hexagonal core arrangements), the system creates an asymmetric spatial distribution that optimizes pumping light coupling into each core, compensating for manufacturing variations in rare-earth metal doping concentrations.

Inventive Principle:
Principle #4Asymmetry

2Device complexity

If core portions are connected without rotation, then device complexity is reduced, but signal light quality deteriorates due to amplification gain deviation

Engineering Contradiction:
Improveconnection configurationVSAvoidsignal light quality
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent performs preliminary rotation of core portions around the cladding axis before connecting the optical amplifying fibers. This preliminary configuration adjustment ensures that the spatial arrangement of cores is optimized for uniform pumping light distribution and amplification gain, preventing signal quality deterioration before the connection is even made.

Inventive Principle:
Principle #10Preliminary action

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

The solution effectively reduces amplification gain deviations to within desirable limits, ensuring consistent signal light quality and transmission performance across all core portions, enhancing the reliability and efficiency of multi-core optical fiber systems.

Implementation Method 1

a multi-core optical fiber amplifier using a rare-earth-doped multi-core optical fiber having a plurality of cores which are doped with rare-earth metal as an amplification medium

Methodology Applied
Scientific EffectOptical amplification: Light

Data Source

PatentEP3012926B1Amplification-use multicore optical fiber device and multicore optical fiber amplifier
Publication Date: 2018.04.25 FURUKAWA ELECTRIC CO LTD
  • EP3012926B1 patent drawingFigure 1~2B
  • EP3012926B1 patent drawingFigure 3~4
  • EP3012926B1 patent drawingFigure 5~6

AI summary

Provided is a multi-core optical amplifying fiber device that includes a plurality of multi-core optical amplifying fibers including a plurality of core portions doped with amplification medium and a cladding portion formed at outer peripheries of the plurality of core portions; and a connection portion connecting the core portions of the plurality of multi-core optical amplifying fibers to one another. The connection portion connects the core portions to restrain deviation, between every connected core portions, of amplification gain for a total length of the core portions connected one another. Hereby a multi-core optical amplifying fiber device restraining deviation of amplification gain at each core portion and a multi-core optical fiber amplifier using the same are provided.