Optical Fiber Coating with Low Modulus Primary Layer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Optical fibers with reduced Young's modulus for improved lateral pressure characteristics face challenges in maintaining uniformity and increasing transmission loss at low temperatures due to deformation and peeling issues during manufacturing and screening tests.
Innovation Solution
An optical fiber design featuring a primary resin layer with a Young's modulus of 0.4 MPa or less and an outer diameter of 185 μm to 202 μm, combined with a secondary resin layer having a glass transition temperature of 60° C. to 95° C. and controlled linear expansion coefficients, to reduce residual stress and prevent peeling, while maintaining excellent lateral pressure characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the Young's modulus of the primary resin layer is reduced to improve lateral pressure characteristics, then lateral pressure characteristics are improved, but uniformity deteriorates due to deformation during manufacturing
Solution Approach 1:
The patent applies parameter changes by precisely controlling the outer diameter of the primary resin layer within 185-202 μm and its Young's modulus to 0.4 MPa or less at 23°C. This optimized parameter combination allows the primary resin layer to be soft enough for excellent lateral pressure characteristics while maintaining dimensional stability during manufacturing to ensure uniformity.
Solution Approach 2:
The patent uses a composite coating resin layer structure consisting of a primary resin layer with low Young's modulus (0.4 MPa or less) and a secondary resin layer with controlled glass transition temperature (60-95°C). This composite structure combines the softness needed for lateral pressure protection with the dimensional stability required for manufacturing uniformity.
2Reliability
If the Young's modulus of the primary resin layer is reduced to improve lateral pressure characteristics, then lateral pressure characteristics are improved, but transmission loss increases at low temperatures due to peeling
Solution Approach 1:
The patent controls the glass transition temperature of the secondary resin layer to 60-95°C and the difference in linear expansion coefficients between the two resin layers to 0.7×10⁻⁴/°C or less. These parameter controls prevent excessive peeling at low temperatures while maintaining the low Young's modulus (0.4 MPa or less) of the primary resin layer for excellent lateral pressure characteristics.
Solution Approach 2:
The composite coating resin layer structure with specifically controlled properties (primary layer: Young's modulus ≤0.4 MPa; secondary layer: Tg = 60-95°C; matched thermal expansion) prevents peeling-induced transmission loss at low temperatures while preserving the lateral pressure protection benefits of the soft primary resin layer.
3Reliability
If the outer diameter of the primary resin layer is increased to improve lateral pressure characteristics, then lateral pressure characteristics are improved, but manufacturing precision deteriorates due to deformation
Solution Approach 1:
The patent optimizes the outer diameter of the primary resin layer to a specific range of 185-202 μm. This precise parameter control ensures the primary resin layer is thick enough to provide excellent lateral pressure characteristics while remaining thin enough to maintain manufacturing precision and uniformity during the coating process.
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
The solution provides an optical fiber with excellent uniformity and no increase in transmission loss under low temperature environments, ensuring improved lateral pressure characteristics without compromising transmission capacity.
Implementation Method 1
the primary resin layer has a Young's modulus of 0.4 MPa or less at 23° C.
Implementation Method 2
the secondary resin layer has a glass transition temperature of 60° C. or more and 95° C. or less
Implementation Method 3
the difference between the average linear expansion coefficient of the coating resin layer in the range of 60° C. to 140° C. and the average linear expansion coefficient of the coating resin layer in the range of −60° C. to 0° C. is 0.7×10−4/° C. or less
Data Source
AI summary
An optical fiber comprises a glass fiber comprising a core and a cladding; and a coating resin layer coating the glass fiber, wherein the coating resin layer has a primary resin layer in contact with the glass fiber and coating the glass fiber and a secondary resin layer coating the outer periphery of the primary resin layer, the primary resin layer has a Young's modulus of 0.4 MPa or less at 23° C. and the primary resin layer has an outer diameter of 185 μm or more and 202 μm or less, the secondary resin layer has a glass transition temperature of 60° C. or more and 95° C. or less, and the difference between the average linear expansion coefficient of the coating resin layer in the range of 60° C. to 140° C. and the average linear expansion coefficient of the coating resin layer in the range of −60° C. to 0° C. is 0.7×10−4/° C. or less.