Bend-Resistant Single Mode Optical Fiber with Annular Cladding
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Solution Overview
Problem
Optical fibers in access and fiber-to-the-premises networks face significant bend losses due to tight bend radii and mechanical stress, leading to signal attenuation and degradation.
Innovation Solution
A bend-resistant single-mode optical fiber with a specific refractive index profile and cladding structure, comprising a glass core and annular regions with controlled refractive indices, providing low macrobend and microbend attenuation losses, and enhanced effective area for reduced signal nonlinearities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If optical fiber is deployed in tight bend environments (small bend radii), then the fiber can be installed in compact spaces and access networks, but bend losses increase causing signal attenuation
Solution Approach 1:
The patent applies local quality by creating distinct annular regions within the cladding, each with different refractive index characteristics. The first annular region has a refractive index profile that differs from both the core and the outer cladding, allowing localized control of optical field distribution to reduce bend-induced losses while maintaining compact installation capability
Solution Approach 2:
The patent changes physical parameters by precisely controlling the refractive index distribution through dopant concentration profiles in different annular regions. By adjusting the refractive index parameters in the first annular region relative to the core and outer cladding, the fiber achieves improved bend resistance and reduced signal attenuation in tight bend conditions
2Reliability
If the core and cladding structure is optimized for bend resistance, then macrobend and microbend losses are reduced, but the manufacturing complexity increases
Solution Approach 1:
The patent segments the cladding into multiple annular regions with distinct refractive index profiles. This segmentation allows each region to perform a specific function in managing the optical field under bend conditions, achieving superior bend resistance through the coordinated interaction of segmented regions rather than a uniform structure
Solution Approach 2:
The patent employs composite material principles by combining different dopant compositions in adjacent annular regions to create a composite cladding structure. This composite approach enables tailored optical properties in each region, optimizing bend resistance while managing the complexity through systematic material composition design
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 exhibits superior bend resistance and low signal attenuation across various bending conditions, maintaining high performance at high bit rates and reducing signal degradation, thereby improving network reliability and efficiency.
Implementation Method 1
Optical waveguide fiber is disclosed herein that is bend resistant and single moded at the wavelength of 1260 nm and at higher wavelengths
Implementation Method 2
The maximum relative refractive index of the glass core is less than 0.45%. The minimum relative refractive index of the annular ring region is less than or equal to −0.1%. The magnitude of the relative refractive index of the annular inner region is low, less than 0.05%
Data Source
AI summary
Optical waveguide fiber that is bend resistant and single mode at 1260 nm and at higher wavelengths. The optical fiber includes a core of radius R1 and cladding, the cladding having an annular inner region of radius R2, an annular ring region, and an annular outer region. The annular ring region starts at R2, and the ratio R1/R2 is greater than 0.40.