Skewed Laser Ablation for Optical Fiber Cladding
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Solution Overview
Problem
Existing methods for processing optical fibers to couple external optical signals are inefficient, as they often result in unclean surfaces, reduced optical and mechanical quality, and health risks due to the use of hydrofluoric acid, or fail to provide precise selective ablation, especially for non-rotationally symmetrical fibers.
Innovation Solution
A method involving the use of a laser beam to process the optical cladding along the longitudinal axis of the optical fiber, with the laser beam's effective axis skewed relative to the fiber's axis, allowing for precise and uniform ablation by targeting the edge region, enabling controlled access to the optical core.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If hydrofluoric acid is used to remove the optical cladding, then the cladding can be etched and removed, but the surface becomes unclean and optical and mechanical quality are reduced
Solution Approach 1:
The patent replaces chemical etching with laser ablation. The laser beam processes the optical cladding through ablation rather than chemical reaction, eliminating the need for hydrofluoric acid. This substitution of mechanical/photonic processing for chemical processing resolves the contradiction by achieving cladding removal while maintaining surface quality, as the laser can be precisely controlled to ablate material without leaving chemical residues or damaging the underlying surface.
Solution Approach 2:
The patent changes the processing parameters by using a skewed laser beam angle (5-45 degrees relative to the fiber axis) and controlling the laser power density. This parameter change enables selective ablation of the cladding while preserving the optical core and maintaining surface integrity. The specific parameter settings allow precise control over the ablation depth and surface quality, resolving the contradiction between material removal and surface preservation.
2Loss of substance
If hydrofluoric acid is used for processing, then the cladding can be removed, but health risks are introduced
Solution Approach 1:
The patent replaces the hazardous chemical process with laser ablation, eliminating the use of hydrofluoric acid entirely. This substitution removes the health risks associated with handling and disposing of corrosive chemicals while maintaining the ability to effectively remove the optical cladding. The laser process is contained and controllable, presenting no comparable health hazards.
3Loss of substance
If mechanical technologies with abrasive means are used, then material can be removed, but selective ablation cannot be achieved for non-rotationally symmetrical fibers
Solution Approach 1:
The patent replaces abrasive mechanical technologies with laser ablation. The laser beam can be precisely positioned and controlled to ablate material selectively based on optical absorption differences between the cladding and core, rather than relying on mechanical contact. This enables selective removal of cladding from non-rotationally symmetrical fibers without requiring the fiber to rotate or be perfectly positioned, as the laser can target specific regions with high precision.
4Loss of substance
If laser processing is performed with perpendicular or near-perpendicular radiation, then the fiber can be processed, but precise selective ablation within the cladding cannot be achieved
Solution Approach 1:
The patent introduces asymmetry in the laser beam configuration by radiating at an angle of 5-45 degrees relative to the fiber axis rather than perpendicularly. This asymmetric angle, combined with the skewed effective axis of the laser beam, enables the beam to selectively interact with the cladding material while avoiding the optical core. The angular configuration creates a geometry where the laser energy is concentrated on the cladding surface, achieving precise selective ablation that perpendicular radiation cannot provide.
Solution Approach 2:
The patent moves the laser processing from a two-dimensional perpendicular approach to a three-dimensional skewed approach. By introducing an angular dimension and skewing the effective axis relative to the fiber axis, the laser can selectively process the cladding along the longitudinal axis without affecting the core. This dimensional change enables precise control over which portions of the fiber are processed, achieving selective ablation that was not possible with perpendicular radiation alone.
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 approach allows for reliable, precise, and controlled processing of optical fibers, providing a uniform and reproducible coupling point for external optical signals with reduced health risks and improved optical and mechanical quality.
Implementation Method 1
the optical cladding is processed via a laser beam at a coupling point of the optical fiber
Implementation Method 2
so that the optical cladding is processed via an edge region of the laser beam
Data Source
AI summary
A method of processing an optical fiber for coupling an external optical signal. The optical fiber has a longitudinal axis, an optical core, and an optical cladding. The method includes processing the optical cladding with a laser beam at a coupling point of the optical fiber along the longitudinal axis between a start and an end region. During the processing, an effective axis of the laser beam is arranged skew with respect to the longitudinal axis of the optical fiber so that the optical cladding is processed via an edge region of the laser beam, and the effective axis of the laser beam is guided along a movement axis which is parallel to or substantially parallel to the longitudinal axis of the optical fiber.