Optical Fiber Diameter Control for Microbending Loss Reduction
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Solution Overview
Problem
Optical fibers with thin coating resin thickness are prone to increased microbending loss when densely housed in cables due to irregular stress, leading to transmission loss issues.
Innovation Solution
An optical fiber design featuring a glass fiber with a core and cladding, where the cladding has a lower refractive index than the core, and a coating resin with a specific ultraviolet curing resin composition, ensuring a reduced outer diameter while maintaining sufficient coating thickness to prevent irregular bending and enhance light confinement, thereby reducing microbending loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the coating resin thickness is reduced to decrease the outer diameter of the optical fiber, then the outer diameter is reduced, but the coating resin becomes susceptible to irregular stress and lateral pressure, causing increased microbending loss and transmission loss
Solution Approach 1:
The patent applies parameter changes by precisely controlling the outer diameter of the glass fiber within 99-101 μm and the coating resin outer diameter within 160-170 μm. This specific parameter range maintains sufficient coating thickness (30-40 μm) to protect against irregular stress while achieving the desired reduced overall diameter, thereby resolving the contradiction between miniaturization and transmission reliability
Solution Approach 2:
The patent implements beforehand cushioning by ensuring the coating resin has sufficient thickness (30-40 μm) before the optical fiber is subjected to lateral pressure or irregular stress in cable housing. This pre-established protective layer absorbs and distributes stress, preventing microbending of the glass fiber and maintaining low transmission loss even at reduced diameters
2Reliability
If the coating resin thickness is increased to protect against irregular stress, then transmission loss is reduced, but the outer diameter of the optical fiber increases
Solution Approach 1:
The patent resolves this contradiction by optimizing the parameter range of the coating resin outer diameter to 160-170 μm, which corresponds to a specific thickness range (30-40 μm) when applied to a glass fiber with outer diameter of 99-101 μm. This optimized parameter range provides sufficient mechanical protection while minimizing the increase in overall fiber diameter
3Volume of moving object
If the glass fiber outer diameter is reduced to minimize space occupation, then the outer diameter is decreased, but the fiber becomes more sensitive to bending stress and lateral pressure
Solution Approach 1:
The patent applies parameter changes by precisely controlling the glass fiber outer diameter within the narrow range of 99-101 μm. This precise parameter control, combined with the optimized coating resin dimensions, maintains sufficient mechanical strength and resistance to bending stress while achieving the goal of reduced diameter and space occupation
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 effectively suppresses transmission loss while reducing the fiber diameter, maintaining low bending loss and microbending loss, even under lateral pressure, and supports low-loss transmission of light across various wavelengths without the need for transmitter-receiver upgrades.
Implementation Method 1
The coating resin includes a cured material of an ultraviolet curing resin composition
Implementation Method 2
A refractive index of the cladding is lower than a refractive index of the core
Data Source
AI summary
An optical fiber includes a glass fiber and a coating resin covering an outer periphery of the glass fiber. The glass fiber includes a core and a cladding. An outer diameter of the glass fiber is 99 μm or larger and 101 μm or smaller. The coating resin includes a cured material of an ultraviolet curing resin composition. An outer diameter of the coating resin is 160 μm or larger and 170 μm or smaller. A mode field diameter for light having a wavelength of 1310 nm is 7.2 μm or larger and 8.2 μm or smaller. Bending loss at a wavelength of 1550 nm when wound in a ring shape having a radius of 10 mm is 0.1 dB/turn or less. Bending loss at the wavelength of 1550 nm when wound in the ring shape having the radius of 7.5 mm is 0.5 dB/turn or less.