Multi-Laser Beam Superposition for Overlapping Scan Fields
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Solution Overview
Problem
Existing laser material processing systems are limited by process speed, beam deflection system inertia, and large installation space, preventing complete overlap of scanning areas in the target plane, especially in applications requiring small laser spot diameters and short focal lengths.
Innovation Solution
A device with multiple laser beam sources of different central wavelengths, using dichroic mirrors to spectrally combine and superimpose laser beams, allowing independent deflection and focusing through a common optics system for complete overlap of scanning areas.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If multiple laser beam sources with different central wavelengths are used and spectrally combined through dichroic mirrors, then complete overlap of scanning areas is achieved, but device complexity increases
Solution Approach 1:
The patent combines multiple laser beams of different wavelengths into a single optical path using dichroic mirrors. The first dichroic mirror combines beams from different laser sources, and the second dichroic mirror further combines additional beams, allowing all beams to be focused by a single objective lens onto the same target area, achieving complete overlap of scanning areas.
Solution Approach 2:
Dichroic mirrors serve as intermediary optical elements that selectively reflect specific wavelength ranges while transmitting others. These mirrors act as mediators to combine multiple laser beams of different wavelengths into a common optical path without requiring separate focusing optics for each beam, thereby reducing overall system complexity while achieving precise spatial overlap.
2Volume of stationary object
If a common focusing optics system is used for all laser beams, then installation space is reduced, but the ability to independently modulate each beam is limited
Solution Approach 1:
The patent segments the laser beam generation into multiple independent laser sources, each capable of independent modulation, while using a common focusing optics system. Deflection devices are positioned before the dichroic mirrors to allow independent spatial modulation of each beam before they are combined, maintaining adaptability while reducing installation space through shared optics.
Solution Approach 2:
The patent resolves the conflict by operating in different spatial dimensions: independent modulation is achieved through deflection devices in the beam path before combination, while the common focusing optics operates in the focal plane to achieve spatial overlap. This dimensional separation allows both independent control and space efficiency.
3Power
If beam deflection systems with large installation space are used, then high-power laser radiation can be deflected, but overlap of working ranges of individual laser beams is prevented
Solution Approach 1:
The patent merges multiple laser beams into a common optical path using dichroic mirrors and a shared focusing optics system. This consolidation allows high-power laser radiation to be deflected and focused through a compact arrangement, enabling complete overlap of working ranges in the target plane while maintaining the capability to handle high power through appropriate optical element selection.
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
Enables a significant increase in productivity by allowing up to 100% overlap of scanning areas, scalable and parallelizable laser material processing, particularly in micro SLM, SLE, and stereolithography.
Implementation Method 1
The laser beams are combined in a superposition arrangement by means of one or more dichroic mirrors tuned to the different central wavelengths
Implementation Method 2
dichroic mirrors tuned to the different central wavelengths
Implementation Method 3
one or more focusing optics for focusing the laser beams into the target plane
Implementation Method 4
at least two laser beam sources, a deflection device for each of the laser beam sources
Data Source
Figure 1~2
Figure 3
Figure 4~5
AI summary
The invention relates to a method and an apparatus for scanning a target plane (PE) with a plurality of laser beams, in particular for laser material processing. The apparatus has at least two laser beam sources (Fi), a deflection device (AEi) for each laser beam source (Fi) and for dynamically deflecting a laser beam emitted by the respective laser beam source (Fi), one or more focusing optical units (FLi, O) for focusing the laser beams into the target plane (PE) and a superposition arrangement for combining the laser beams that have propagated through the deflection device (AEi). In the process, the laser beam sources (Fi) emit laser beams with different central wavelengths, wherein the superposition arrangement comprises one or more dichroic mirrors (DSi) which combine the laser beams. The method and the apparatus facilitate a complete overlap of the scanning regions of the individual laser beams.