Optical Fiber Eccentricity Control via Fourier Analysis
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge is to suppress optical fiber breaks during manufacturing, particularly for fibers with small outer diameters, where the frequency of breakage increases due to eccentricity of the glass fiber and subsequent stress concentrations in the resin coating layer.
Innovation Solution
The solution involves an optical fiber with a glass fiber coated by a resin layer, where the eccentricity of the glass fiber is measured and analyzed using Fourier transform to ensure that the largest amplitude of eccentricity is 6 μm or less and the wavelength at which this amplitude is largest is 0.1 m or more. Additionally, the manufacturing process includes forming the resin coating layer with an outer diameter of 190 μm or less and using a vibration damper and a turning roller fixed separately from other device members to stabilize the fiber during pulling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the outer circumferential diameter of the resin coating layer is reduced to increase productivity, then the frequency of optical fiber breaks increases due to increased eccentricity and stress concentration
Solution Approach 1:
The patent applies parameter changes by precisely controlling the outer circumferential diameter of the resin coating layer to 190 μm or less, and by controlling the eccentricity parameters (largest amplitude ≤6 μm, wavelength ≥0.1 m) through Fourier transform analysis. This allows miniaturization for higher productivity while maintaining reliability by optimizing the specific parameter ranges that prevent stress concentration and breakage.
2Ease of manufacture
If the glass fiber eccentricity is increased to simplify the manufacturing process, then stress concentration occurs in the resin coating layer leading to fiber breaks
Solution Approach 1:
The patent employs feedback by measuring the eccentricity of the glass fiber at multiple points along the axial direction, applying Fourier transform to obtain the amplitude spectrum, and using this information to control and adjust the manufacturing process. This ensures that the largest amplitude is kept at 6 μm or less and the wavelength at 0.1 m or more, preventing stress concentration while maintaining manufacturing feasibility.
3Device complexity
If the circumference length of rollers is reduced to decrease device complexity, then vibration damping capability decreases leading to increased fiber breaks
Solution Approach 1:
The patent addresses vibration issues by ensuring that the circumference length of the largest roller (among turning and guide rollers) is 0.2 m or more. This dimensional parameter is specifically controlled to provide adequate vibration damping capability during the pulling process, preventing fiber breaks caused by excessive vibration while managing device complexity.
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 effectively reduces the frequency of optical fiber breaks by minimizing eccentricity-induced stress concentrations and ensuring stable fiber pulling, thereby enhancing manufacturing efficiency and fiber reliability.
Implementation Method 1
damping vibration of the optical fiber by using a vibration damper installed downstream of the curing device and upstream of a turning roller
Implementation Method 2
curing the resin coating layer by using a predetermined curing device
Data Source
AI summary
An optical fiber includes a glass fiber, and a resin coating layer covering an outer circumference of the glass fiber. In a spectrum acquired by measuring an amount of eccentricity of the glass fiber from a central axis based on an outer circumference of the resin coating layer at a plurality of measurement points set at a predetermined interval in an axial direction of the glass fiber and applying Fourier transform of a waveform representing the amount of eccentricity at each of the plurality of measurement points, a largest value of amplitude of the amount of eccentricity is 6 μm or less.