Multicore Optical Fiber with Double Cladding for Stable Core Identification
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional end face observation of multicore optical fibers experiences brightness variations of markers and cores depending on the illumination light's incident direction, making core identification unstable.
Innovation Solution
The multicore optical fiber features a glass optical fiber with a double cladding structure, where the outer cladding has a higher refractive index than the inner cladding, ensuring observation light propagates and leaks uniformly, stabilizing the end face image brightness regardless of illumination direction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single cladding structure is used in conventional MCF, then the structure is simple and easy to manufacture, but the end face image brightness varies depending on illumination direction, making core identification unstable
Solution Approach 1:
The cladding is divided into two separate claddings: an inner cladding with lower refractive index and an outer cladding with higher refractive index. This segmentation allows each cladding to perform specific functions - the inner cladding provides the primary optical confinement while the outer cladding ensures uniform light leakage from all directions, stabilizing the end face image brightness regardless of illumination direction.
Solution Approach 2:
The patent introduces asymmetry in the refractive index distribution by making the outer cladding have a higher refractive index than the inner cladding. This asymmetric design creates a refractive index gradient that ensures light from any incident direction will eventually leak uniformly through the outer cladding, eliminating the directional brightness variation problem.
2Stability of the object's composition
If the outer cladding has higher refractive index than inner cladding, then light propagation is uniform from all directions, but the refractive index distribution becomes more complex
Solution Approach 1:
The patent changes the refractive index parameter distribution by assigning different refractive index values to the inner and outer claddings. Specifically, the outer cladding has a higher refractive index than the inner cladding, creating a controlled parameter variation that ensures uniform light leakage. This parameter change stabilizes the end face image brightness while maintaining manufacturability through standard optical fiber drawing processes.
3Measurement precision
If conventional single cladding is used, then manufacturing is simpler, but core and marker identification reliability decreases due to brightness variations
Solution Approach 1:
The cladding is segmented into inner and outer layers with distinct refractive index characteristics. This segmentation improves measurement precision by ensuring uniform light leakage that consistently illuminates cores and markers from all directions, making identification accurate regardless of illumination angle. The segmented structure can be manufactured using established multi-layer fiber drawing techniques.
Solution Approach 2:
By changing the refractive index parameter of the outer cladding to be higher than the inner cladding, the patent achieves consistent light leakage behavior that enhances identification accuracy. This parameter change creates a refractive index profile that ensures uniform brightness distribution, improving core and marker detectability while remaining compatible with conventional fiber manufacturing methods.
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
This configuration allows for stable core identification by uniformly dispersing observation light, reducing brightness variations and enhancing the reliability of core recognition.
Implementation Method 1
the illumination light propagates in the MCF, the illumination light is confined in a high refractive index region and propagates with low propagation loss
Implementation Method 2
the outer cladding has a refractive index higher than a refractive index of the inner cladding
Implementation Method 3
the illumination light is confined in a high refractive index region and propagates with low propagation loss, whereas the illumination light propagates with high propagation loss while leaking out in a low refractive index region
Data Source
AI summary
A multicore optical fiber (MCF) according to one embodiment of the present invention enables stable core identification. The MCF comprises a glass optical fiber and a resin coating. The glass optical fiber includes a plurality of cores, a marker, and cladding. On a cross-section of the MCF, the arrangement of the centers of the cores and the center of the marker has no rotational symmetry with respect to the center of the cross-section. The cladding includes an inner cladding that surrounds the cores and the marker, and an outer cladding that is provided on the outer peripheral surface of the inner cladding and has a refractive index higher than that of the inner cladding.