Light-Diffusing Optical Fiber Symmetric Illumination
Solution Overview
Problem
Current light-diffusing fiber systems with a single light source and no reflective end coating provide asymmetric illumination, which is aesthetically inferior and lacks symmetry with respect to viewing angle, limiting their application in broad-area illumination applications.
Innovation Solution
Incorporating a symmetric distribution of scattering centers in the secondary coating of the light-diffusing fiber, which controls the concentration and thickness of scattering centers to achieve symmetric scattering intensity across azimuthal directions, allowing for symmetric illumination without the need for counter-propagating light.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single light source is used without reflective end coating, then device complexity is reduced, but illumination symmetry deteriorates
Solution Approach 1:
The patent applies local quality by creating a secondary coating with non-uniform scattering center distribution. The scattering centers are concentrated in specific regions of the secondary coating to locally modify light scattering behavior, achieving symmetric illumination patterns without requiring complex system structures or reflective coatings. This localized modification of optical properties resolves the contradiction between simple system structure and symmetric illumination.
2Shape
If scattering centers are added to secondary coating, then illumination symmetry is improved, but manufacturing complexity increases
Solution Approach 1:
The patent employs parameter changes by systematically varying the concentration, size, and spatial distribution of scattering centers in the secondary coating. By optimizing these parameters, the invention achieves symmetric illumination while maintaining manufacturability. The scattering centers are incorporated at controlled concentrations during the coating fabrication process, allowing for scalable production without excessive complexity.
3Illumination intensity
If scattering center concentration is increased, then scattering intensity is improved, but light transmission is reduced
Solution Approach 1:
The patent applies local quality by creating a secondary coating with non-uniform scattering center distribution. The scattering centers are concentrated in specific regions of the secondary coating to locally modify light scattering behavior, achieving symmetric illumination patterns without requiring complex system structures or reflective coatings. This localized modification of optical properties resolves the contradiction between simple system structure and symmetric illumination.
Solution Approach 2:
The patent employs partial action by incorporating scattering centers at optimized concentrations rather than maximum possible concentrations. The scattering centers are distributed at levels sufficient to achieve symmetric illumination patterns while maintaining adequate light transmission. This partial implementation optimizes the balance between scattering intensity and light transmission without requiring excessive scattering center concentration.
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 enables light-diffusing fibers to provide symmetric illumination with a single light source, enhancing aesthetic appeal and expanding their application in broad-area illumination by ensuring consistent light distribution across viewing angles.
Implementation Method 1
The scattering is accomplished by incorporating nanostructural voids within or throughout the core and/or cladding regions of the fiber. The voids are low-index regions, typically filled with a gas, and have dimensions on the order of the wavelength of the light propagating through the fiber. The refractive index contrast between the voids and surrounding dense glass matrix effects scattering of the light.
Implementation Method 2
The refractive index contrast between the voids and surrounding dense glass matrix effects scattering of the light.
Data Source
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AI summary
A light-diffusing optical fiber that provides a symmetric intensity distribution of forward and backward scattered light is described. The fiber includes a secondary coating that contains scattering centers. Control of the thickness of the secondary coating and concentration of scattering centers provides control over the distribution of scattered intensity. More symmetric distributions of scattered light intensity are realized by increasing the thickness of the secondary coating and/or the concentration of scattering centers in the secondary coating. Representative scattering centers include oxide nanoparticles.