Coated Optical Fiber Microbending Low-Temperature Trade-Off
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional coated optical fibers face challenges in maintaining microbending loss resistance and low-temperature characteristics, as increasing the secondary coating's Young's modulus to enhance rigidity leads to increased tensile stress on the primary coating, causing cracks and deteriorating transmission characteristics, while reducing the primary coating's Young's modulus to improve microbending resistance compromises low-temperature performance.
Innovation Solution
Optimizing the Young's modulus of the primary coating layer to 1.2 MPa or less and the secondary coating layer to 700 MPa or more, with a tin content of 70 ppm or less in the primary coating layer, and controlling the total tin content in both layers to 70 ppm or less, using an ultraviolet ray-curable resin composition containing specific photopolymerization initiators and reactive diluents, to balance microbending loss resistance and low-temperature characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the Young's modulus of the secondary coating layer is increased to enhance rigidity, then the microbending loss resistance is improved, but the tensile stress on the primary coating layer increases causing cracks and deteriorating transmission characteristics
Solution Approach 1:
The patent applies parameter changes by precisely controlling the Young's modulus of the secondary coating layer to be 700 MPa or more (specific range optimized) and the primary coating layer to be 0.55 MPa or less, while also controlling tin content to 70 ppm or less. This multi-parameter optimization resolves the contradiction by finding the specific parameter ranges where both high rigidity for microbending resistance and low stress for transmission reliability are achieved simultaneously.
2Strength
If the Young's modulus of the primary coating layer is decreased to improve microbending resistance, then the cushioning performance is enhanced, but the low-temperature characteristic deteriorates due to increased transmission loss
Solution Approach 1:
The patent resolves this contradiction through parameter changes by optimizing the Young's modulus of the primary coating layer to 0.55 MPa or less while simultaneously controlling the tin content to 70 ppm or less. This specific parameter combination achieves both excellent microbending loss resistance and maintained low-temperature characteristics, overcoming the trade-off between cushioning performance and thermal stability.
3Reliability
If the breaking strength of the primary coating layer is enhanced to prevent voids, then the low-temperature characteristic is improved, but the Young's modulus increases compromising microbending loss resistance
Solution Approach 1:
The patent applies parameter changes by decoupling the relationship between breaking strength and Young's modulus through precise control of tin content (70 ppm or less) and Young's modulus (0.55 MPa or less). This enables the primary coating layer to achieve both high breaking strength for void prevention and low Young's modulus for microbending resistance, resolving the apparent trade-off through multi-parameter optimization.
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 enhances both microbending loss resistance and low-temperature characteristics by reducing transmission losses at low temperatures, while maintaining appropriate mechanical strength and handling properties.
Implementation Method 1
an ultraviolet ray-curable resin composition containing at least one kind of an acylphosphine oxide-based photopolymerization reaction initiator
Data Source
AI summary
Provided is a coated optical fiber excellent in both characteristics of the microbending loss resistance and the low-temperature characteristic. The coated optical fiber 1 comprises an optical fiber 10 that has a cladding layer composed of glass formed on an outer periphery of a glass core, a primary coating layer 20 that coats an outer periphery of the optical fiber 10, and a secondary coating layer 30 that coats an outer periphery of the primary coating layer 20, wherein the primary coating layer 20 has a Young's modulus of 1.2 MPa or less, the secondary coating layer 30 has a Young's modulus of 700 MPa or more, and the primary coating layer 20 contains tin in a content of 70 ppm or less.