Optical Fiber Mode Field Diameter for Splice Loss Reduction
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Solution Overview
Problem
The difference in mode field diameters between G652 and G657 single-mode optical fibers results in significant splice loss during circuit construction, adversely affecting the performance of optical fiber networks.
Innovation Solution
An optical fiber design with a large mode field diameter of 8.7 to 9.5 µm and improved bending resistance, achieving compatibility with both G652 and G657 fibers, with macrobending losses reduced to less than 0.1 dB at specific radii and wavelengths, and a flexible outer diameter range to accommodate various applications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If G652 single-mode optical fiber is used for long-distance transmission and LAN construction, then compatibility with original optical fiber is improved, but splice loss increases when jointed with G657 fiber due to mode field diameter difference
Solution Approach 1:
The patent changes the mode field diameter parameter of the optical fiber to 8.6±0.5μm, which matches the G657 fiber specification. This parameter adjustment enables compatibility with G657 fibers while reducing splice loss in mixed-fiber environments, directly resolving the technical contradiction between compatibility and splice loss.
2Strength
If G657 single-mode optical fiber is used for LAN construction, then bending resistance is improved, but splice loss increases when jointed with G652 fiber due to mode field diameter difference
Solution Approach 1:
The patent adopts a mode field diameter of 8.6±0.5μm that aligns with G657 fiber specifications, thereby inheriting the excellent bending resistance characteristics of G657 fibers. Simultaneously, this parameter setting reduces splice loss when connecting with G652 fibers, effectively resolving the contradiction between bending resistance and splice loss.
3Ease of operation
If a single optical fiber type is used for all applications, then deployment simplicity is improved, but performance optimization for different environments deteriorates
Solution Approach 1:
The patent creates a universal optical fiber solution with mode field diameter of 8.6±0.5μm that can be used in both G652 and G657 fiber networks. This single fiber type can be deployed in long-distance transmission, LAN construction, and access networks, providing consistent performance across different environments while simplifying deployment operations.
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 optical fiber achieves full compatibility with existing standards, reduces splice loss, and provides excellent bending resistance, making it suitable for diverse network environments while optimizing space utilization.
Implementation Method 1
an optical fiber includes, from inside to outside, a core layer 1, a buffer cladding layer 3, a recessed cladding layer 5, a deep fluorine doped layer 7, an external cladding layer 9
Data Source
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AI summary
An optical fiber includes, from inside to outside, a core layer, a buffer cladding layer, a recessed cladding layer, a deep fluorine doped layer, an external cladding layer, and a coating layer. The core layer is germanium doped silica. A refractive index difference between the core layer and silica is 0.37 % to 0.5 %. A refractive index of the buffer cladding layer gradual changes along the buffer cladding layer. A refractive index difference between an internal interface of the buffer cladding layer contacting with the core layer and silica is -0.05 % to 0.1 %. A refractive index of an external interface of the buffer cladding layer contacting with the recessed cladding layer is equal to a refractive index of the recessed cladding layer. A refractive index difference between the recessed cladding layer and silica is -0.12 % to -0.2 %. A refractive index difference between the deep fluorine doped layer and silica is -0.3 % to -0.5 %. The external cladding layer is made of silica. The coating layer is coated outside the external cladding layer. The optical fiber has large mode field diameter and good bending resistance.