Metal Ion-Doped UV Filter for Wavelength Selectivity

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Solution Overview

Problem

Existing UV light filters for deep UV regions are complex, costly, and suffer from low transmission and high angular dependence, limiting their effectiveness in disinfection applications.

Innovation Solution

A wavelength selective filter using a host matrix doped with metal ions, which allows high transmission of specific deep UV wavelengths while absorbing others, reducing complexity and cost, and minimizing angular dependence.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If an interference filter is used for deep UV wavelength selection, then wavelength selectivity is achieved, but transmission in the bandpass region is low

Engineering Contradiction:
Improvewavelength selectivityVSAvoidtransmission in bandpass region
Core Design Contradiction:
Measurement precisionVSLoss of energy

Solution Approach 1:

The patent changes the fundamental operating parameters of the filter by using absorption-based filtering instead of interference-based filtering. The filter material uses specific metal ions (Fe3+, Cr3+, Mn2+, Co2+, Ni2+, Cu2+, Zn2+) with carefully controlled concentrations (0.01-10 wt%) to achieve wavelength selection through absorption rather than interference, thereby maintaining high transmission in the bandpass region while achieving the desired wavelength selectivity.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs composite filter materials consisting of metal ion-doped glass or ceramic matrices. These composite materials combine the optical filtering properties of metal ions with the structural stability and UV transparency of glass/ceramic hosts, enabling high transmission deep UV filtering that overcomes the limitations of conventional interference filters.

Inventive Principle:
Principle #40Composite materials

2Measurement precision

If an interference filter is used for deep UV wavelength selection, then wavelength selectivity is achieved, but the filter shows high dependence on angle of incidence

Engineering Contradiction:
Improvewavelength selectivityVSAvoidangular dependence
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The patent fundamentally changes the filtering mechanism from interference-based to absorption-based. The absorption coefficient of metal ions is inherently independent of angle of incidence for normal to oblique angles, eliminating the angular dependence problem that plagues interference filters. This allows the filter to maintain consistent wavelength selectivity across a wide range of incident angles.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If an interference filter is used for deep UV wavelength selection, then wavelength selectivity is achieved, but the construction is complex and difficult

Engineering Contradiction:
Improvewavelength selectivityVSAvoidfilter construction
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts the wavelength-selective function from the complex multilayer interference structure and concentrates it in the chemical composition of the filter material itself. By doping metal ions into a UV-transparent glass or ceramic matrix, the filter achieves wavelength selectivity through the inherent absorption characteristics of the metal ions, eliminating the need for precise multilayer deposition and complex periodic refractive index modulation.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent uses metal ion-doped glass/ceramic composite materials that integrate the wavelength-selective function directly into the bulk material properties. This approach simplifies the filter construction to a single homogeneous layer, replacing the complex multilayer interference structure with a readily manufacturable doped glass or ceramic filter.

Inventive Principle:
Principle #40Composite materials

4Measurement precision

If an interference filter is used for deep UV wavelength selection, then wavelength selectivity is achieved, but manufacturing precision requirements are high

Engineering Contradiction:
Improvewavelength selectivityVSAvoiddeposition precision
Core Design Contradiction:
Measurement precisionVSManufacturing precision

Solution Approach 1:

The patent extracts the wavelength-selective function from the complex multilayer interference structure and concentrates it in the chemical composition of the filter material itself. By doping metal ions into a UV-transparent glass or ceramic matrix, the filter achieves wavelength selectivity through the inherent absorption characteristics of the metal ions, eliminating the need for precise multilayer deposition and complex periodic refractive index modulation.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the fundamental operating parameters of the filter by using absorption-based filtering instead of interference-based filtering. The filter material uses specific metal ions (Fe3+, Cr3+, Mn2+, Co2+, Ni2+, Cu2+, Zn2+) with carefully controlled concentrations (0.01-10 wt%) to achieve wavelength selection through absorption rather than interference, thereby maintaining high transmission in the bandpass region while achieving the desired wavelength selectivity.

Inventive Principle:
Principle #35Parameter changes

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 filter achieves high transmission in the desired deep UV range, enhancing disinfection efficiency by selectively transmitting antibacterial and antiviral wavelengths while excluding harmful ones, with reduced luminescence and minimal sensitivity to incident angle.

Implementation Method 1

The filter material has a transmission region within a deep ultraviolet (UV) wavelength range... a first portion of the UV light... is transmitted through the wavelength selective filter

Methodology Applied
Scientific EffectAbsorption (EM radiation): Absorption (EM radiation)

Data Source

PatentEP3940434B1Ultraviolet light wavelength selective filter
Publication Date: 2024.09.25 THE BOEING CO
  • EP3940434B1 patent drawingFigure 1
  • EP3940434B1 patent drawingFigure 2~3
  • EP3940434B1 patent drawingFigure 4~5

AI summary

A wavelength selective filter includes a filter material. The filter material includes a host matrix doped with metal ions. The filter material has a transmission region within a deep ultraviolet (UV) range such that UV light at wavelengths within the transmission region is transmitted through the filter material.