Laser Beam Shaping for Crack-Guided Machining of Transparent Materials
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Solution Overview
Problem
Existing laser machining technologies face challenges in effectively processing materials that are transparent to laser beams, as they struggle to achieve precise modifications and efficient material separation due to the transparency of the materials, which limits the ability to form desired geometries and crack formations.
Innovation Solution
The apparatus employs a beam splitting element to split the input beam into component beams, which are then focused into different partial regions of a focal zone using a focusing optical unit, allowing for the introduction of the focal zone at various angles relative to the workpiece, enabling material modifications associated with crack formation, such as Type III modifications, which facilitate material separation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a conventional single beam is used for laser machining transparent materials, then the laser beam can pass through the material, but the material cannot be effectively modified or separated due to transparency
Solution Approach 1:
The laser beam is divided into multiple component beams using a beam shaping device with phase imposition. These component beams are then focused into different partial regions of the focal zone, creating multiple focal points within the transparent material. This segmentation allows the laser to interact with the material at multiple locations simultaneously, enabling effective modification and crack formation despite material transparency.
Solution Approach 2:
Different partial regions of the focal zone receive different component beams with specific phase relationships. This creates localized intensity distributions and focal characteristics tailored to specific regions within the material. The local quality variation enables precise control over where and how material modifications occur, achieving both precision and reliability in transparent material processing.
2Use of energy by moving object
If the laser beam is focused into a single focal point, then the energy concentration is high, but the ability to form desired geometries and crack patterns is limited
Solution Approach 1:
The beam shaping device transforms the conventional single-point focal geometry into a three-dimensional focal zone with multiple partial regions. By imposing phase variations across the beam profile, the system creates a distributed focal structure that extends in multiple dimensions within the material. This dimensional expansion maintains energy concentration while enabling complex geometry and crack pattern formation.
Solution Approach 2:
The phase imposition mechanism allows dynamic control over the distribution of component beams within the focal zone. By adjusting phase parameters, the system can dynamically reconfigure the focal pattern to match different machining requirements, achieving both high energy concentration and geometric adaptability for various crack formations and material modifications.
3Manufacturing precision
If a beam splitting element with phase imposition is used to create multiple component beams, then material modification precision improves, but the device complexity increases
Solution Approach 1:
The patent replaces complex mechanical beam splitting systems with an optical phase modulation approach. Instead of using multiple mirrors, lenses, or mechanical beam directors, the system uses a beam shaping device that imposes phase variations directly on the laser beam. This substitution reduces mechanical complexity while achieving precise focal zone positioning through optical field control.
Solution Approach 2:
The beam shaping device controls the position and distribution of component beams by changing optical phase parameters rather than physical component positions. This parameter-based control allows precise adjustment of focal zone characteristics without complex mechanical adjustments, reducing device complexity while maintaining high positioning precision for material modification.
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 flexible and precise laser machining of transparent materials by forming focal zones with varying geometries and angles, enabling efficient material separation and modification, including the creation of cracks that aid in the separation process.
Implementation Method 1
the first input beam is split by the beam splitting element by phase imposition on the first input beam
Implementation Method 2
a focusing optical unit assigned to the first beam shaping device and configured to image the plurality of component beams output coupled from the first beam shaping device into at least one focal zone
Implementation Method 3
Material modifications associated with a crack formation in the material are produced in the material by exposing the material to the at least one focal zone
Data Source
AI summary
An apparatus for laser machining a workpiece with a material transparent to the laser machining includes a first beam shaping device with a beam splitting element for splitting a first input beam into a plurality of component beams, and a focusing optical unit configured to image the plurality of component beams into at least one focal zone. The first input beam is split by the beam splitting element by phase imposition on the first input beam. The component beams are focused into different partial regions of the at least one focal zone for forming the at least one focal zone. The at least one focal zone is introduced by the focusing optical unit into the material for laser machining the workpiece. Material modifications associated with a crack formation in the material are produced in the material by exposing the material to the at least one focal zone.