Optical Waveguide Diffuser Structure for Homogeneous Lateral Emission

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Solution Overview

Problem

Existing diffusers for medical therapies like PDT, EVLT, and LITT are costly, complex to produce, and struggle with homogeneity and reusability issues, particularly in achieving uniform lateral emission and compatibility with high power densities.

Innovation Solution

A lighting system with a diffuser element that includes a diffuser base body with scattering elements arranged parallel to its longitudinal axis, enclosed by devices to homogenize emission intensity, and features reflectors to manage forward emission and scattering, using materials like glass or quartz for robustness and thermal stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If scattering particles are embedded in a polymer matrix to create diffuser elements, then lateral emission can be achieved, but manufacturing complexity and cost increase significantly

Engineering Contradiction:
Improvelateral emissionVSAvoidmanufacturing complexity
Core Design Contradiction:
Illumination intensityVSDevice complexity

Solution Approach 1:

The patent employs a porous glass structure as the diffuser base body, where the porous nature provides scattering centers for light diffusion. This eliminates the need for embedding separate scattering particles in a polymer matrix, thereby simplifying manufacturing while achieving the desired lateral emission effect.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The patent uses composite glass-ceramic materials with controlled crystalline phases that provide inherent light scattering properties. This replaces complex polymer-scatterer composites with a more manufacturable glass-based composite that achieves similar optical diffusion without the manufacturing complexity of particle embedding.

Inventive Principle:
Principle #40Composite materials

2Ease of manufacture

If conventional diffuser manufacturing methods are used, then diffuser elements can be produced, but manufacturing cost and complexity increase

Engineering Contradiction:
Improvediffuser productionVSAvoidmanufacturing process complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent divides the diffuser manufacturing process into separate functional zones: a proximal end for light coupling, a middle section with controlled porosity for diffusion, and a distal end for emission. This segmentation allows each zone to be optimized independently and simplifies the overall manufacturing process by treating different sections with different processing parameters.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent controls the porosity parameter along the length of the diffuser base body, with lower porosity at the proximal end for efficient light coupling and higher porosity at the distal end for enhanced lateral emission. This gradual parameter change simplifies manufacturing by using continuous processing variables rather than discrete assembly steps.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If diffuser elements are designed for single use, then manufacturing costs can be reduced, but reusability and cost-effectiveness decrease

Engineering Contradiction:
Improvecost-effectivenessVSAvoidreusability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent describes a diffuser base body made from glass or glass-ceramic that can be manufactured at low cost through simplified processes. While the material itself is durable, the overall design allows for economical replacement units that maintain high performance across multiple uses, effectively combining disposable cost advantages with reusable reliability.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

4Manufacturing precision

If homogeneity of lateral emission is improved, then radiation uniformity increases, but manufacturing precision requirements increase

Engineering Contradiction:
Improveemission homogeneityVSAvoidmanufacturing difficulty
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent implements local quality variations in the diffuser base body by controlling porosity distribution along its length. The proximal end has lower porosity for efficient light coupling, while the distal end has higher porosity for enhanced lateral emission. This localized property variation achieves homogeneous overall emission while using straightforward manufacturing techniques.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent creates a porous structure with porosity exceeding 50% in the distal section to ensure sufficient light scattering. This excessive porosity in specific zones compensates for variations in manufacturing precision and ensures homogeneous lateral emission even with moderate manufacturing tolerances.

Inventive Principle:
Principle #16Partial or excessive action

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 solution provides cost-effective, reproducible, and reusable diffusers with homogeneous lateral emission, suitable for high power densities, and maintains Lambertian radiation behavior, addressing manufacturing and reusability challenges.

Implementation Method 1

The diffuser base body (43) comprises at least one scattering element (43.6), wherein the at least one scattering element (43.6) is arranged essentially parallel to a longitudinal axis (43.2) of the diffuser base body (43)

Methodology Applied
Scientific EffectLight scattering: Scattering

Implementation Method 2

Furthermore, a reflector surface (47) is provided, in particular at the distal end of the diffuser base body (43)

Methodology Applied
Scientific EffectLight reflection: Reflection

Implementation Method 3

enclosed by devices to homogenize emission intensity

Methodology Applied
Scientific EffectHomogenization of emission:

Data Source

PatentEP3688503B1Illumination system comprising an optical waveguide with a diffuser element, and method for producing and/or at least structuring a diffuser base body partially or in sections
Publication Date: 2026.03.04 SCHOTT AG
  • EP3688503B1 patent drawingFigure 1~2
  • EP3688503B1 patent drawingFigure 3a~5c
  • EP3688503B1 patent drawingFigure 6a~7

AI summary

The invention relates to an illumination system (1), particularly for a medical treatment and/or diagnosis system, comprising at least one laser light source (10), and an optical waveguide (30) that, on its proximal end, can be connected to and/or associated with the at least one laser light source (10), and, on its distal end, comprises a diffuser element (40) with a longitudinal axis extending perpendicularly to the coupling surface of the optical waveguide into the diffuser element, said diffuser element irradiating light over the active length (40.2) thereof laterally to the longitudinal axis, during the operating state thereof, and said diffuser element (40) comprising at least one diffuser base body (43) containing at least one scattering element (43.6), said at least one scattering element (43.6) being oriented along the longitudinal axis (43.2) of the diffuser base body (43) substantially parallel thereto, or arranged at an angle to the longitudinal axis. Devices for homogenising the irradiation intensity along the longitudinal axis (43.2) of the diffuser base body (43) are provided on the distal end of the diffuser base body (43) and/or surrounding the transition region between the optical waveguide (30) and the diffuser base body (43) and/or the diffuser base body (43) itself, at least partially or in sections. During the operating state, the intensity distribution of the lateral irradiation of the illumination system deviates by a maximum of ± 50%, preferably a maximum of ± 30% and most preferably a maximum of ± 5% from the mean lateral irradiation intensity. The invention also relates to a method for producing and/or structuring a diffuser base body (43) at least partially or in sections.