Optical Fiber Coating Rigidity for Low Micro-Bending Loss
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Reducing the diameter of optical fibers in optical cables increases micro-bending loss, which is a challenge for achieving high density and efficient information transmission.
Innovation Solution
Manufacturing optical fibers with a glass diameter of 125 µm or less, surrounded by primary and secondary resin layers, and setting the lateral and bending rigidities within specific ranges to suppress micro-bending loss, allowing for higher fiber density and efficient transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the diameter of optical fibers is reduced to increase the number of fibers per unit cross-sectional area, then the density of optical fibers in the cable is improved, but the micro-bending loss increases
Solution Approach 1:
The patent applies parameter changes by precisely controlling the glass fiber diameter within the range of 75 μm to 125 μm and the Young's modulus within 60 GPa to 80 GPa. These parameter adjustments optimize the balance between achieving high fiber density and suppressing micro-bending loss, resolving the contradiction between increasing fiber quantity and maintaining transmission quality.
Solution Approach 2:
The patent uses composite materials by combining glass fibers with specific resin coatings. The resin coating layer provides mechanical protection and stabilizes the glass fiber, reducing micro-bending effects. This composite structure allows the use of smaller diameter fibers while maintaining low micro-bending loss through the protective and stabilizing properties of the resin material.
2Quantity of substance
If the diameter of glass fiber is reduced to increase fiber density, then the quantity of fibers in the cable is improved, but the transmission loss after cabling increases
Solution Approach 1:
The patent employs parameter changes by optimizing the glass fiber diameter to 75-125 μm and Young's modulus to 60-80 GPa. These specific parameter ranges ensure that the fibers can be densely packed while maintaining adequate mechanical strength and resistance to micro-bending, thereby keeping transmission loss after cabling within acceptable limits.
Solution Approach 2:
The resin coating acts as an intermediary between the glass fiber and the external environment. It provides mechanical protection, distributes stresses uniformly, and prevents direct contact between adjacent fibers that could cause micro-bending. This intermediary layer enables high fiber density while maintaining low transmission loss by isolating each fiber from mechanical disturbances.
3Area of stationary object
If the diameter of optical fiber is reduced for high density, then the area efficiency is improved, but the micro-bending resistance deteriorates
Solution Approach 1:
The patent applies parameter changes by controlling the glass fiber diameter within 75-125 μm and the Young's modulus within 60-80 GPa. These parameter optimizations ensure that even with reduced diameter for better area utilization, the fibers maintain sufficient micro-bending resistance through appropriate material properties and structural design.
Solution Approach 2:
The patent uses composite materials by coating the glass fiber with a resin layer. This composite structure enhances the micro-bending resistance of the thin glass fiber by providing external mechanical support and distributing bending stresses. The resin coating acts as a protective shell that prevents the fragile glass fiber from suffering micro-bending damage while allowing the overall fiber diameter to remain small for high density packing.
Data Source
Figure 1
Figure 2
AI summary
Provided is a method for manufacturing an optical fiber that includes a glass fiber with a diameter of 125 µm or less, a primary resin layer, and a secondary resin layer having a diameter of from 150 µm to 210 µm. The method includes: a process of obtaining a lateral rigidity D0, a bending rigidity H0, a transmission loss α1 at a wavelength of 1.55 µm before being mounted in the optical cable, and a transmission loss α2 at a wavelength of 1.55 µm after being mounted in the optical cable with respect to a reference optical fiber; and a process of setting a range of Dg satisfying Formula (3) at 125 µm or less when a lateral rigidity of the optical fiber as shown in Formula (1) is set as D [N/m2], and a bending rigidity of the optical fiber as shown in Formula (2) is set as H [N·m2] with respect to the optical fiber. D=c11−R0R2c2+c3E2−E110∑i,j,kcijklog10R2−R1R2−R0ilog10E1E2jlog10R0R2k+E11H∝πR04E0+πR24−R14E220.3≥D/H2D0/H02α2−α1+α13