Optical Fibre Squeezing for Adjustable Laser Beam Quality
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Solution Overview
Problem
Current laser processing technologies, such as cutting and welding, face limitations due to fixed beam quality, which restricts the ability to optimize process parameters for varying metal types and thicknesses, leading to suboptimal cutting quality and efficiency.
Innovation Solution
A laser processing apparatus featuring a beam delivery system with a squeezing mechanism comprising a periodic surface, allowing the beam parameter product to be varied by adjusting the squeezing force, enabling control over beam radius, divergence, and output beam profile, thereby optimizing focal spot size and divergence for different materials and thicknesses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a fixed beam quality laser is used, then the laser processing system is simple and reliable, but the processing quality and efficiency cannot be optimized for varying metal types and thicknesses
Solution Approach 1:
The patent applies dynamics by making the beam parameter product adjustable rather than fixed. The squeezing mechanism dynamically changes the optical properties of the optical fiber, allowing the beam quality to be varied according to different processing requirements. This enables the same laser system to adapt to different metal types and thicknesses by changing the beam parameter product, resolving the contradiction between adaptability and device complexity.
2Productivity
If the focal spot size is reduced to increase energy power density, then cutting efficiency improves, but the optical depth of field limit prevents achieving sufficiently small focal spots for thick materials
Solution Approach 1:
The patent applies parameter changes by modifying the beam parameter product through the squeezing mechanism. By changing this fundamental optical parameter, the system can achieve different focal spot sizes and divergence angles that are optimized for specific material thicknesses. This allows the focal spot size to be reduced for thick materials without being constrained by the fixed optical depth of field, thereby improving both cutting efficiency and precision.
3Productivity
If the beam divergence is increased to widen the kerf for better assist gas flow, then assist gas can reach the bottom of thick cuts, but the molten region becomes wider reducing cutting precision
Solution Approach 1:
The patent applies parameter changes by independently controlling the beam parameter product, which simultaneously affects both focal spot size and divergence angle. By adjusting this parameter, the system can optimize the balance between kerf width (for assist gas flow) and focal spot size (for cutting precision). This allows the assist gas to reach the bottom of thick cuts while maintaining a narrow molten region for precise cutting.
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 solution provides greater flexibility in laser processing, enabling high beam quality for precise cutting of stainless steel and low beam quality for thicker mild steel, resulting in improved cutting speeds and reduced edge roughness, while also allowing for automatic tuning of industrial lasers based on material parameters.
Implementation Method 1
a squeezing mechanism, having a periodic surface defined by a pitch; a length of optical fibre is located adjacent to the periodic surface; the squeezing mechanism is configured to squeeze the periodic surface and the length of optical fibre together with a squeezing force
Data Source
AI summary
Apparatus (10) for laser processing a material (11), which apparatus comprises a laser (1) and a beam delivery cable (2), wherein: the laser (1) is connected to the beam delivery cable (2); the beam delivery cable (2) is configured to transmit laser radiation (13) emitted from the laser (1), and the laser radiation (13) is defined by a beam parameter product (4); and the apparatus (10) is characterized in that: the apparatus (10) includes at least one squeezing mechanism (5) comprising a periodic surface (6) defined by a pitch (7); a length (8) of optical fibre (9) that forms part of the laser (1) and/or the beam delivery cable (2) is located adjacent to the periodic surface (6); and the squeezing mechanism (5) is configured to squeeze the periodic surface (6) and the length (8) of the optical fibre (9) together with a squeezing force (12); whereby the beam parameter product (4) is able to be varied by adjusting the squeezing force (12).