Nested Capillary Preform Control for Low-Ovality Hollow-Core Fiber
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Solution Overview
Problem
Existing methods for producing anti-resonant hollow-core fibers face challenges in maintaining precision and reproducibility due to oval deformations of capillary blanks during thermal stretching, which affect the positioning and alignment of anti-resonance elements, leading to non-uniformity and higher-order mode propagation.
Innovation Solution
The method involves pre-producing capillary blanks with nested capillaries, setting specific geometric parameters such as equilibrium pressures, taper ratios, and cross-sectional dimensions to maintain a degree of ovality less than 1.025, ensuring precise positioning and reproducible drawing of anti-resonance elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If thermal stretching is performed to form capillary blanks, then the capillary blanks are formed with nested capillaries, but oval deformations occur during the process affecting positioning precision
Solution Approach 1:
The patent applies parameter changes by optimizing the geometric dimensions (external diameter, internal diameter, wall thickness) and thermal stretching parameters (temperature, stretching ratio, equilibrium pressure) to control the degree of ovality. By carefully selecting these parameters, the capillary blanks maintain circular cross-sections with minimal deformation, ensuring precise positioning of anti-resonance elements while still enabling the thermal stretching process to form the nested capillary structure.
2Manufacturing precision
If geometric parameters are optimized to reduce ovality, then positioning precision improves, but the complexity of parameter control increases
Solution Approach 1:
The patent applies preliminary action by pre-calculating and pre-setting the optimal geometric parameters and thermal stretching conditions before the actual manufacturing process. The equilibrium pressure, taper ratio, and cross-sectional dimensions are determined in advance through design and simulation, allowing the manufacturing process to proceed with standardized parameters that automatically achieve the desired precision without requiring complex real-time control adjustments.
3Measurement precision
If capillary blanks are produced with high precision, then assembly accuracy improves, but the reproducibility of the drawing process becomes more difficult to maintain
Solution Approach 1:
The patent applies parameter changes by establishing standardized geometric parameters and thermal stretching conditions that create a consistent starting point for the drawing process. By controlling the initial capillary blank dimensions and properties through optimized manufacturing parameters, the process ensures that each batch of capillary blanks has uniform characteristics, making the subsequent drawing process more reproducible and reliable.
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 facilitates accurate assembly and reduces oval deformations, enabling precise positioning of anti-resonance elements, thereby ensuring high precision and reproducibility in the production of anti-resonant hollow-core fibers with reduced geometric errors.
Implementation Method 1
thermal stretching of the capillary blank ensemble to form the capillary blank
Data Source
AI summary
The invention relates to the production of an anti-resonant hollow-core fiber consisting of a capillary blank and a sleeve tube. The capillary blank comprises an external capillary and a nested internal capillary, and is stretched to a maximum external diameter ODARE_cap and a maximum wall thickness WTARE_caP. The blank is mounted on the inside of the sleeve tube. In order to retain the advantages of the pre-produced capillary blank with respect to ease of assembly and precision, while keeping the associated drawbacks owing to ovality low and predictable, it is proposed that the geometric internal diameter and external diameter of the external capillary and of the internal capillary, as well as ODARE_cap and WTARE_caP, are aligned in relation to one another in such a way that the ARE-external capillary of the capillary blank has a degree of ovality of less than 1.025.