Multicore Fiber Structure with Orthogonal Deformation Correction

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Solution Overview

Problem

Multicore fibers with non-circular cross-sectional shapes face issues such as decreased accuracy of clad diameter and deterioration of polarization mode dispersion (PMD) characteristics.

Innovation Solution

Incorporating a plurality of core portions arranged in a first radial direction and deformation correction portions in a second radial direction orthogonal to the first radial direction within the cladding portion, along with a low-refractive index portion between the core portions, to inhibit a non-circular cross-sectional shape.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If core portions are arranged in a radial direction to form a multicore fiber, then the fiber can support multiple cores, but the cross-sectional shape becomes non-circular which deteriorates PMD characteristics

Engineering Contradiction:

Improvemulticore capabilityVSAvoidPMD characteristics

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent introduces deformation correction portions arranged in a direction substantially orthogonal to the first radial direction to actively create asymmetric stress distribution that counteracts the asymmetric deformation caused by core portions. This controlled asymmetry compensates for the shape distortion, maintaining circular cross-section and improving PMD characteristics while preserving multicore functionality

Inventive Principle:

Principle #4Asymmetry

2Adaptability or versatility

If core portions are arranged in a radial direction, then multiple cores can be formed, but the cross-sectional shape becomes non-circular which decreases clad diameter accuracy

Engineering Contradiction:

Improvemulticore capabilityVSAvoidclad diameter accuracy

Core Design Contradiction:

Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

Deformation correction portions are strategically positioned in a direction substantially orthogonal to the first radial direction to create compensatory stress that counteracts the asymmetric deformation induced by radially arranged core portions. This maintains the circular cross-sectional shape and ensures accurate clad diameter throughout the fiber structure

Inventive Principle:

Principle #4Asymmetry

3Shape

If deformation correction portions are added to correct cross-sectional shape, then circular shape is maintained, but device complexity increases

Engineering Contradiction:

Improvecross-sectional circularityVSAvoidfiber structure complexity

Core Design Contradiction:

ShapeVSDevice complexity

Solution Approach 1:

Deformation correction portions are positioned at specific locations within the cladding portion, arranged in a direction substantially orthogonal to the first radial direction. This localized placement provides shape correction only where needed, minimizing structural complexity while maintaining cross-sectional circularity

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS20250298183A1Multicore fiber and multicore fiber manufacturing method

Publication Date: 2025.09.25 FURUKAWA ELECTRIC CO LTD

AI summary

A multicore fiber includes: a plurality of core portions; a cladding portion surrounding outer peripheries of the plurality of core portions and having a refractive index lower than the plurality of core portions; and a plurality of deformation correction portions arranged inside the cladding portion. The plurality of core portions are arranged in a first radial direction in a cross-section perpendicular to a longitudinal direction of the multicore fiber, and the plurality of deformation correction portions are arranged in a second radial direction substantially orthogonal to the first radial direction, in the cross-section.