Fiber Coupler Fabrication for High-Power Low-Loss Transmission
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Solution Overview
Problem
Conventional fiber coupler fabrication methods are limited in producing low-loss tap fiber couplers capable of handling high optical powers, particularly kW-levels, due to the requirement for large-core or highly-multimode fibers and the need for precise control of phase, polarization, and path length in high-power fiber laser systems.
Innovation Solution
A method involving the fusion of optical fibers' outer claddings over short lengths (not exceeding 3 mm) to create a fiber tap coupler with a low throughput loss, using two separate processing steps: fusing and heating, where the heating step is done without significant fiber pulling, allowing for the handling of up to 80 Watts of optical power with less than 0.2 dB loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional fiber coupler fabrication methods are used, then the manufacturing process is simple, but the optical transmission loss exceeds acceptable limits and high-power handling capability is not achieved
Solution Approach 1:
The fabrication process is divided into two distinct stages: (1) fusing the outer claddings of the fibers over a short length, and (2) heating the second region to complete the coupling. This segmentation allows optimization of each stage independently, achieving low transmission loss through controlled short-length fusing while maintaining manufacturing feasibility.
Solution Approach 2:
The patent applies different processing conditions to different regions of the fiber assembly. The first region undergoes fusing with specific pulling and heating parameters optimized for cladding integration, while the second region receives heating treatment without significant pulling. This local differentiation enables precise control of optical coupling characteristics to minimize transmission loss.
2Power
If large-core or highly-multimode fibers are used to handle high optical power, then the power handling capability increases, but conventional fabrication methods cannot achieve low-loss coupling with these fiber types
Solution Approach 1:
The patent modifies the fabrication parameters specifically for high-power applications by limiting the fusing length to not exceed 3 mm and controlling the heating parameters in the second region. These parameter changes enable successful coupling of large-core and highly-multimode fibers with transmission loss below 0.2 dB, achieving both high power handling (up to 80 Watts) and low loss.
3Stability of the object's composition
If the fusing length is extended to ensure proper fiber integration, then the structural integration improves, but the optical transmission loss increases
Solution Approach 1:
The patent applies partial action by limiting the fusing process to a short length (not exceeding 3 mm) which is sufficient for adequate structural integration of the outer claddings, without extending the fusion zone further than necessary. This prevents excessive fusion that would increase transmission loss, while still achieving the required structural stability for high-power operation.
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 proposed method enables the fabrication of fiber tap couplers with negligible optical transmission loss across a wide range of input powers, from 10 Watts to 80 Watts, and supports the use of various fiber types, including single-mode, large-mode-area, and multimode fibers, effectively addressing the limitations of conventional methods.
Implementation Method 1
pulling and heating the first and second optical fibers
Implementation Method 2
tangibly fusing a first outer cladding of a first optical fiber with a second outer cladding of a second optical fiber
Implementation Method 3
heating a second region of the first and second optical fibers
Data Source
AI summary
A method for fabricating an optical fiber coupler device includes a step of tangibly fusing a first outer cladding of a first optical fiber with a second outer cladding of a second optical fiber as a result of pulling and heating the first and second optical fibers at lengths not exceeding 3 mm to form a first region of structurally-integrated with one another first and second optical fibers, and a step of heating a second, neighboring region of these fibers to configure the device to transmit optical power of at least about a hundred Watts and up to at least a kWatt from the input end to the output end with a value of throughput loss not exceeding 0.2 dB.