Optical Delay Device Beam Path Lengthening

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Solution Overview

Problem

Existing optical delay devices for lengthening laser beam paths require significant space and cannot efficiently manage beam path lengthening with minimal installation space, particularly in driver laser arrangements for EUV light sources.

Innovation Solution

The method involves passing the light beam through an optical delay device at least twice along different geometric paths, allowing for manipulation of beam properties and using a configuration of first and second reflective surfaces arranged in grids with overlapping but offset orientations to achieve beam path lengthening with reduced spatial requirements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of moving object

If the beam path is extended through multiple reflections between reflective surfaces, then the beam path length is increased, but the installation space required increases

Engineering Contradiction:
Improvebeam path lengthVSAvoidinstallation space
Core Design Contradiction:
Length of moving objectVSArea of stationary object

Solution Approach 1:

The patent applies dimensionality change by arranging reflective surfaces in three-dimensional space with specific orientations and offsets. The beam path is folded through multiple dimensions using grids of reflective surfaces at different angles, allowing extensive beam path lengthening within a compact footprint by utilizing spatial dimensions rather than simple linear extension

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent implements nesting by arranging multiple grids of reflective surfaces within each other in a compact configuration. The first and second grids with their respective reflective surfaces are nested in space, allowing the beam to traverse through multiple reflection cycles while maintaining a compact overall device structure that minimizes installation space

Inventive Principle:
Principle #7Nested doll (Nesting)

2Length of moving object

If the beam path is extended through tight folding and numerous reflections, then the beam path length is increased, but the device complexity increases

Engineering Contradiction:
Improvebeam path lengthVSAvoiddevice complexity
Core Design Contradiction:
Length of moving objectVSDevice complexity

Solution Approach 1:

The patent segments the beam path extension function into multiple independent grids of reflective surfaces. Each grid acts as a separate module that contributes to the overall beam path lengthening, allowing the complex function to be divided into manageable segments that can be independently designed, aligned, and maintained

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies universality by using identical or similar grids of reflective surfaces for multiple purposes: each grid serves both as a beam directing element and as part of the beam path lengthening mechanism. The first and second grids with their respective reflective surfaces perform multiple functions including beam folding, path extension, and spatial configuration within a unified structural approach

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Reliability

If optical switches are used to block back reflections, then component protection is improved, but the beam path is blocked during switching

Engineering Contradiction:
Improvecomponent protectionVSAvoidbeam transmission
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent applies preliminary action by extending the beam path length before the beam reaches potential damage zones or before subsequent pulses arrive. The optical delay device pre-lengthens the beam trajectory using multiple reflections between grids, creating a time buffer that allows optical switches to block back reflections without interfering with the main beam transmission timeline

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent introduces an intermediary optical delay device between the beam source and the target area. This intermediary device uses grids of reflective surfaces to create a delayed beam path, serving as a mediator that separates the timing of beam transmission from back reflection blocking, allowing optical switches to protect components without blocking the main beam path during operation

Inventive Principle:
Principle #24Intermediary (Mediator)

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 effectively lengthens the laser beam path while minimizing the required installation space, allowing for efficient operation in driver laser arrangements and preventing back reflections from damaging components.

Implementation Method 1

multiple reflections of the light beam between the first reflecting surfaces and the second reflecting surfaces to extend the beam path of the light beam

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP3183610B1Method for elongating a travel path of a light beam, optical delay device, and driver laser arrangement comprising said device
Publication Date: 2021.03.03 TRUMPF LASER SYSTEMS FOR SEMICONDUCTOR MANUFACTURING GMBH
  • EP3183610B1 patent drawingFigure 1a~2
  • EP3183610B1 patent drawingFigure 3a~4b
  • EP3183610B1 patent drawingFigure 5a~6

AI summary

The invention relates to a method for elongating a travel path of a light beam, in particular a laser beam, having the following steps: coupling the light beam into an intermediate space (20) between a plurality of first reflective surfaces (18) and a plurality of second reflective surfaces (19) which face the first reflective surfaces (18), reflecting the light beam multiple times between the first reflective surfaces (18) and the second reflective surfaces (19) in order to elongate the travel path of the light beam (7), and coupling the light beam out of the intermediate space (20), wherein the light beam undergoes the steps of being incoupled, reflected multiple times, and outcoupled for at least one first pass and a second pass, and the light beam traverses a different beam path in the intermediate space (20) during the first pass than the beam path during the second pass.