Multicore Fibre Preform Assembly for Precise Core Positioning
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Solution Overview
Problem
Existing methods for producing multi-core fibers face challenges such as complex stacking processes, geometric errors, and contamination issues, leading to non-uniformity and reduced fiber strength due to bubbles and scattering, which limit the transmission capacity and reliability of multi-core fibers.
Innovation Solution
A method involving the removal of a part-tube segment from a receiving tube to create core rod receiving cut-outs, followed by precise insertion of core rods and a central filling rod, then fusion with a jacketing tube to form a preform, ensuring accurate alignment and reduced geometric errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the stack and draw method is used to produce multi-core fibers, then the transmission capacity is enhanced through spatial multiplexing, but the manufacturing complexity increases and stacking errors occur leading to geometric imperfections
Solution Approach 1:
The preform manufacturing process is segmented into modular steps: creating a receiving tube with controlled internal geometry, inserting core rods into predetermined positions, and fusing with a jacketing tube. This segmentation allows each step to be optimized independently, reducing overall manufacturing complexity while maintaining high transmission capacity through precise core positioning.
Solution Approach 2:
The receiving tube is prepared in advance with a controlled internal diameter and cross-sectional area before core rod insertion. This preliminary action establishes the geometric framework that guides subsequent core rod placement, eliminating the need for complex stacking operations and reducing stacking errors while enabling high-density core arrangements for enhanced transmission capacity.
2Quantity of substance
If multiple individual rods with different diameters are stacked to achieve high packing density, then the core packing efficiency is improved, but the number of interfaces increases leading to bubbles and contaminations
Solution Approach 1:
The problematic multiple interfaces between differently sized rods are eliminated by extracting the complex stacking approach and replacing it with a simplified receiving tube structure. The receiving tube provides a single continuous matrix that accommodates core rods without creating numerous interfaces, thereby removing the source of bubbles and contaminations while maintaining high packing density through optimized tube geometry.
Solution Approach 2:
The receiving tube is designed with uniform material composition and consistent wall thickness, creating a homogeneous structure that eliminates interfaces between different rod materials. This homogeneity prevents bubble formation and contamination at interfaces, while the controlled internal diameter ensures high packing density of core rods within the uniform matrix.
3Manufacturing precision
If ultrasonic drilling is used to create holes in glass cylinders for core rod insertion, then core positioning is achieved, but geometric errors increase and fabrication costs rise
Solution Approach 1:
Instead of drilling holes into a solid glass cylinder to create core rod positions, the invention inverts the approach by using a receiving tube with a controlled internal diameter that naturally defines the core rod insertion paths. This inversion eliminates the need for ultrasonic drilling and subsequent polishing operations, reducing geometric errors and fabrication complexity while maintaining precise core positioning through the tube's inherent geometry.
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 method enhances the precision and homogeneity of the preform and final fiber, reducing the need for post-processing and minimizing scattering, thereby improving transmission capacity and fiber strength.
Implementation Method 1
fusing the jacketing tube containing the receiving tube to form the preform
Data Source
AI summary
A preform manufactured by a method which includes removing a part-tube segment from a center of a receiving tube so that the receiving tube has a core rod receiving cut-out which is formed as a remaining annular sector with two opposite edges, axially introducing a central filling rod into the receiving tube so that the receiving tube contains the central filling rod, inserting a core rod in a radial direction from outside into the core rod receiving cut-out between the two opposite edges of the remaining annular sector so that the receiving tube contains the first core rod, axially introducing the receiving tube containing the core rod and the central filling rod into a jacketing tube so as to obtain a jacketing tube containing the receiving tube, and fusing the jacketing tube containing the receiving tube to form the preform.