Hollow-Core Fiber Preform Extrusion for Precise Microstructure
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Solution Overview
Problem
There is a need to produce hollow-core optical fibers and preforms with ease and precision, as the microstructure of hollow-core optical fibers, including dimensions and locations of cladding elements, significantly affects light travel.
Innovation Solution
The method involves extruding a precursor material through a die assembly to form a hollow-core optical fiber preform, using a die assembly comprising inserts and a shell to create structures like outer and inner tubes or spiral panels, ensuring precise alignment and coupling of material portions to achieve the desired microstructure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If traditional methods (laydown and redraws) are used to produce hollow-core preforms, then the process can achieve basic structural formation, but the number of process steps increases and manufacturing complexity rises
Solution Approach 1:
The die assembly is divided into multiple inserts (first insert with mandrel, second insert with column and channel, third insert with spiral member) that can be independently configured and assembled. Each insert creates specific structural features (inner tube, outer tube, spiral panel) that are formed simultaneously in a single extrusion process, eliminating the need for sequential laydown and redraw operations.
2Manufacturing precision
If precise alignment and coupling of material portions are achieved through complex die assembly, then manufacturing precision improves, but device complexity increases
Solution Approach 1:
The die assembly uses a nested structure where the first insert with mandrel is received through the channel of the second insert, and both are housed within the shell. The mandrel and column create concentric annular gaps that guide material flow to form precisely aligned nested tubes. This nesting approach maintains precise geometric relationships without requiring complex external alignment mechanisms.
Solution Approach 2:
The channel in the second insert acts as an intermediary that receives and positions the mandrel from the first insert. The channel's geometry controls the spacing and alignment between the mandrel and column, ensuring precise annular gap formation. This intermediary structure simplifies the overall alignment process by providing a built-in positioning mechanism.
3Stability of the object's composition
If multiple inserts and components are used to form complex hollow-core structures, then structural stability and unique geometries are achieved, but the device complexity and manufacturing difficulty increase
Solution Approach 1:
The die assembly merges multiple functional components (mandrel, column, spiral member) into a single integrated extrusion process. All structural features (inner tube, outer tube, spiral panel) are formed simultaneously from material extruded through the assembled inserts, creating a stable hollow-core preform in one operation. This combining approach reduces the number of separate manufacturing steps while maintaining structural integrity.
Solution Approach 2:
The invention controls structural parameters through the geometric parameters of the die inserts. By adjusting the dimensions, spacing, and configurations of the mandrel, column, and spiral member, precise control is achieved over the resulting preform's wall thickness, hollow core dimensions, and spiral panel geometry. This parameter control ensures structural stability without requiring complex post-processing.
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 allows for the production of hollow-core preforms with improved structure stability, reduces process steps like laydown and redraws, and enables the formation of unique geometries that are difficult to achieve otherwise, enhancing the efficiency and precision of fiber manufacturing.
Implementation Method 1
heating the precursor material such that a viscosity of the precursor material reaches about 10³ to about 10⁷ poise
Implementation Method 2
a first material portion extruded from the first annular gap and a second material portion extruded from the second annular gap may be coupled upon extrusion from the die assembly
Data Source
AI summary
Methods and systems for producing a hollow-core optical fiber preform and/or components thereof are described herein. In some embodiments, the method may include providing a precursor material, extruding the precursor material through a die assembly to a shaped body, and forming a hollow-core optical fiber preform or a component thereof from the shaped body. In some embodiments, providing the precursor material may include one of: heating the precursor material such that a viscosity of the precursor material reaches about 103 to about 107 poise, or forming a paste comprising a glass powder and a binder. In some embodiments, the hollow-core optical fiber preform may include an outer tube. In some embodiments, the hollow-core optical fiber preform may further include one of an inner tube coupled to the outer tube, or a spiral coupled to the outer tube.