Pivotable Laser Interference Optics for Rotating Surface Structuring

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing laser interference structuring methods are limited by the inability to freely change the direction of interfering laser beams without reducing the interference effect, making it unsuitable for high-speed beam deflection systems and difficult to access areas, such as inside pipes or depressions.

Innovation Solution

A laser-optical arrangement that includes a laser beam source with beam splitters and reflecting elements, where at least one beam splitter or reflecting element can be pivoted to achieve a phase shift and allow continuous rotation of the interference pattern, enabling the direction of interfering partial beams to be changed and maintaining interference effectiveness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If the direction of interfering partial beams is changed arbitrarily, then the processing area can be expanded, but the interference effect is lost or reduced

Engineering Contradiction:
Improveprocessing areaVSAvoidinterference effect
Core Design Contradiction:
Area of stationary objectVSReliability

Solution Approach 1:

The beam splitter is made pivotable about an axis perpendicular to the optical axis, allowing dynamic adjustment of the beam direction while maintaining the interference effect. This dynamic element enables the interference pattern to be rotated and directed onto different areas of the substrate without losing the interference effect, thus resolving the contradiction between expanding processing area and maintaining interference effectiveness.

Inventive Principle:
Principle #15Dynamics

2Manufacturing precision

If partial beams are guided parallel at large distance, then interference can be achieved locally, but the method is unsuitable for high-speed beam deflection systems

Engineering Contradiction:
Improvelocal interference precisionVSAvoidprocessing speed
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

By making the beam splitter pivotable, the system can rapidly change beam directions to cover larger substrate areas while maintaining precise local interference patterns. This enables high-speed processing by allowing the use of fast beam deflection systems without sacrificing the precision of local interference structuring.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the angular parameter of the beam splitter to control the direction of interfering beams. By adjusting this parameter, the system can adapt to different processing requirements, achieving both precise local structuring and high-speed processing of larger areas.

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If the beam splitter is pivoted by a large angle, then the interference pattern can be rotated, but the path difference becomes unequal

Engineering Contradiction:
Improvepattern rotation capabilityVSAvoidinterference condition
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The pivotable beam splitter provides dynamic control over the interference pattern orientation. By carefully controlling the pivot angle within limits that maintain equal path lengths, the system can rotate the interference pattern to different orientations while preserving the precision interference conditions.

Inventive Principle:
Principle #15Dynamics

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 enhances productivity by allowing for larger surface structures to be formed in shorter times and enables interference processing in previously difficult-to-access areas, with the ability to continuously rotate the interference pattern by 90° and increase processing speed to at least 1 m²/min.

Implementation Method 1

The laser beam is split into at least two partial beams by at least one beam splitter

Methodology Applied
Scientific EffectOptical reflection: Reflection

Implementation Method 2

The resulting partial beams strike reflective elements and at least one further beam splitter

Methodology Applied
Scientific EffectOptical transmission: Refraction

Implementation Method 3

The resulting partial beams strike reflective elements and at least one further beam splitter

Methodology Applied
Scientific EffectOptical reflection: Reflection

Implementation Method 4

at least two interfering partial beams strike a substrate surface to be processed

Methodology Applied
Scientific EffectOptical interference: Interference

Implementation Method 5

at least one of the beam splitters or at least one of the reflecting elements can be pivoted or is pivoted about an angle θ perpendicular to the optical axis of a partial beam by the usually specified 45° angle, so that a phase shift between the partial beams can be achieved

Methodology Applied
Scientific EffectPhase shift:

Data Source

PatentEP3466598B1Laser optical arrangement for laser interference processing, in particular laser structuring of surfaces
Publication Date: 2021.07.28 FRAUNHOFER GESELLSCHAFT ZUR FORDERUNG DER ANGEWANDTEN FORSCHUNG EV
  • EP3466598B1 patent drawingFigure 1
  • EP3466598B1 patent drawingFigure 2(a)~2(b)
  • EP3466598B1 patent drawingFigure 2(c)

AI summary

The invention relates to a laser-optical arrangement for laser interference processing, in particular for laser structuring, in which a laser beam (A) emitted by a laser beam source (1) is split into at least two partial beams (B1, B2) by at least one beam splitter (BS1) and the partial beams (B1, B2) are directed onto reflecting elements (M1, M2) and at least one further beam splitter (BS2) such that at least two interfering partial beams (C and D) strike a surface of a substrate (S) to be processed and/or a second beam path (7).At least one of the beam splitters (BS1, BS2) or at least one of the reflecting elements (M1, M2) is pivotable or pivoted about an angle θ of 45° perpendicular to the optical axis of a partial beam (B1, B2), in which the beam splitters (BS1, BS2) and reflecting elements (M1, M2) are aligned with respect to the respective optical axis of the laser beam (A) or the respective partial beam (B1, B2), so that a phase difference between the interfering partial beams (C, D) can be achieved and the partial beams (B1, B2) interfere from the beam splitter (BS2) last arranged in the beam path of the partial beams (B1, B2) starting from the first beam splitter (BS1).