Two-Stage Laser Beam Homogenizer-Expander for Top-Hat Output

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing laser systems struggle to achieve uniform intensity distribution, particularly in applications requiring a top-hat profile, leading to inefficiencies and energy waste in Gaussian profiles, especially when using non-uniform intensity laser sources.

Innovation Solution

A two-stage laser beam homogenizer-expander system utilizing microlens arrays and holographic diffusers to achieve a near-top-hat intensity profile with minimal light loss, incorporating a first beam shaper to divide beams and a second integrator to define the output distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If Gaussian beam sources are physically truncated by an aperture to form a pseudo-flat top profile, then device complexity and cost are minimized, but energy efficiency deteriorates significantly with waste in the outer regions of the gaussian profile

Engineering Contradiction:

Improvedevice complexityVSAvoidenergy efficiency

Core Design Contradiction:

Device complexityVSLoss of energy

Solution Approach 1:

The patent divides the beam shaping process into two distinct stages: a first integrator that performs initial beam division and homogenization, and a second integrator that performs final homogenization and top-hat profile formation. This segmentation allows each stage to be optimized for its specific function, achieving high efficiency while maintaining uniform intensity distribution.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces engineered diffusers as intermediary elements between the two integrators. These diffusers serve as mediators that redistribute light to eliminate hotspots and achieve uniform intensity distribution, enabling the system to maintain high efficiency while producing the desired top-hat profile.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Device complexity

If a single-stage integrator is used for beam homogenization, then device complexity is reduced, but homogenization performance deteriorates with visible hotspots and non-uniform distribution

Engineering Contradiction:

Improveoptical setup complexityVSAvoidhomogenization performance

Core Design Contradiction:

Device complexityVSManufacturing precision

Solution Approach 1:

The patent implements a two-stage integrator system where the first integrator performs initial beam division and the second integrator performs final homogenization. This segmentation allows each stage to be optimized for its specific function, with the first integrator handling coarse homogenization and the second integrator achieving fine uniformity, thereby eliminating hotspots and achieving superior homogenization performance.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The first integrator performs preliminary homogenization and beam division before the light enters the second integrator. This preliminary action reduces the burden on the second integrator, allowing it to focus on achieving the final uniform top-hat profile with minimal hotspots, thereby improving overall homogenization performance.

Inventive Principle:

Principle #10Preliminary action

3Illumination intensity

If conventional beam shapers are used to achieve uniform intensity distribution, then illumination uniformity is improved, but wavelength adaptability deteriorates with limited spectral range

Engineering Contradiction:

Improveintensity uniformityVSAvoidwavelength adaptability

Core Design Contradiction:

Illumination intensityVSAdaptability or versatility

Solution Approach 1:

The patent designs the optical components, particularly the microlens arrays and engineered diffusers, with universal characteristics that enable them to function effectively across multiple wavelengths. The diffusers are engineered to provide wavelength-independent scattering, allowing the same optical setup to achieve uniform intensity distribution for different laser wavelengths without requiring wavelength-specific optimization.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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

The system provides highly accurate beam shaping with minimal light loss, achieving uniform intensity distribution across multiple wavelengths with no visible hotspots or interference patterns, suitable for applications requiring uniform illumination.

Implementation Method 1

A laser beam integrator or homogenizer is an optical element typically formed by multiple lenslets (microlenses) which divide the incident laser beam/s into an array of smaller beams or 'beamlets'

Methodology Applied

Scientific EffectRefraction: Refraction

Implementation Method 2

the beam may be diffused by a holographic refractive diffuser-exhibiting a custom-engineered surface-that provides a desired output angle and light transmittance above 97%

Methodology Applied

Scientific EffectDiffraction: Diffraction

Implementation Method 3

followed by a lens or other focusing element that superimposes all those beamlets in the target plane

Methodology Applied

Scientific EffectFocusing: Focusing

Data Source

PatentUS12436399B2Multi-wavelength laser beam homogenizer-expander light engine

Publication Date: 2025.10.07 LASERWORLD AG

AI summary

A laser beam homogenizer-expander has a first beam shaper element to divide the incident beams into beamlets along the main optical axis, and a second beam shaper element which defines the top-hat intensity distribution output, thus leading to a 2nd homogenization stage. The laser beam homogenizer-expander also has several light diffusers, mirrors, filters, and output lenses to achieve a good homogenization at the desired output angle.