Optical Fiber Nanoscale Homogeneous Core Low Loss
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current optical fibers have high attenuation due to nanoscale crystalline defects, which is exacerbated by high-speed fiber drawing, leading to increased manufacturing costs when attempting to reduce these defects by lowering draw speed.
Innovation Solution
The optical fiber is designed with a nanoscale structurally homogeneous core by doping the core region with viscosity-reducing dopants, such as alkali and halogen, to reduce nanocrystalline defects and achieve residual axial compressive stress, allowing for low-loss transmission at higher draw speeds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the fiber draw speed is lowered to reduce nanoscale crystalline defects, then the attenuation is reduced, but the manufacturing time and cost increase
Solution Approach 1:
The patent changes the chemical composition parameters of the core by doping with specific concentrations of GeO2 (3-11 mol%), P2O5 (0.5-5 mol%), and B2O3 (0.1-2 mol%). This compositional modification alters the material properties to reduce nanoscale crystalline defect formation during high-speed drawing, thereby achieving low attenuation without sacrificing manufacturing speed
Solution Approach 2:
The patent creates a composite glass composition in the core by combining multiple dopants (GeO2, P2O5, B2O3) with silica. This composite material structure suppresses nanoscale crystallization while maintaining optical transparency, enabling low attenuation at high draw speeds
2Stability of the object's composition
If Ge-dopant is used to increase refractive index, then the index profile is achieved, but scattering loss increases
Solution Approach 1:
The patent applies local quality by creating distinct compositional regions: the core contains GeO2 for high refractive index, while the cladding contains B2O3 for low refractive index. This spatial differentiation of dopant distribution achieves the required index profile while controlling scattering loss in each region
Solution Approach 2:
The patent introduces P2O5 and B2O3 as intermediary substances that modify the glass network structure. These intermediaries suppress nanoscale crystallization of GeO2, thereby reducing scattering loss while maintaining the refractive index enhancement provided by Ge-dopant
Data Source
AI summary
An optical fiber has a core region that is doped with one or more viscosity-reducing dopants in respective amounts that are configured, such that, in a Raman spectrum with a frequency shift of approximately 600 cm−1, the fiber has a nanoscale structure having an integrated D2 line defect intensity of less than 0.025. Alternatively, the core region is doped with one or more viscosity-reducing dopants in respective amounts that are configured such that the fiber has a residual axial compressive stress with a stress magnitude of more than 20 MPa and a stress radial extent between 2 and 7 times the core radius.According to another aspect of the invention a majority of the optical propagation through the fiber is supported by an identified group of fiber regions comprising the core region and one or more adjacent cladding regions. The fiber regions are doped with one or more viscosity-reducing dopants in respective amounts and radial positions that are configured to achieve viscosity matching among the fiber regions in the identified group.