Metal Mirror Multispectral Filter Array With Reduced Angle Shift

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Solution Overview

Problem

Existing multispectral sensor devices face challenges in integrating filter arrays due to difficulties in incorporating linear variable filters or circular variable filters with semiconductor-based sensor elements, leading to reduced spectral range and accuracy, as well as high angle shift values.

Innovation Solution

The use of metal mirrors with a spacer layer structure, such as silver-based mirrors and dielectric layers, to create a multispectral filter array that improves durability, spectral range, and reduces angle shift, allowing for efficient multispectral sensing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If linear variable filters or circular variable filters are integrated with semiconductor-based sensor elements, then spectral filtering capability is achieved, but manufacturing difficulty increases and spectral range is reduced

Engineering Contradiction:
Improveintegration difficultyVSAvoidspectral range
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent changes the fundamental parameters of the filter structure by using metal mirrors with controllable thickness and material composition instead of traditional LVC or CVC filters. This allows for easier integration with semiconductor sensors while maintaining or expanding spectral range through parameter optimization of the metal layer thickness and material properties

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs composite structures combining metal mirrors (such as aluminum, silver, or gold) with dielectric layers or semiconductor substrates. This composite approach enables simplified manufacturing processes compared to traditional variable filters while achieving enhanced spectral coverage and reduced angle shift effects

Inventive Principle:
Principle #40Composite materials

2Measurement precision

If traditional filter arrays are used, then spectral filtering is achieved, but angle shift values increase reducing accuracy

Engineering Contradiction:
Improvespectral accuracyVSAvoidangle shift
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent reduces angle shift by optimizing the thickness and material parameters of the metal mirror layers. By carefully controlling these parameters, the filter achieves minimal angle dependence while maintaining spectral filtering accuracy, directly improving measurement precision without increasing device complexity

Inventive Principle:
Principle #35Parameter changes

3Reliability

If metal mirror-based filter array is used, then durability and spectral range are improved, but manufacturing precision requirements increase

Engineering Contradiction:
ImprovedurabilityVSAvoidfabrication tolerance
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent selects metal materials and thickness parameters that are tolerant to standard semiconductor manufacturing variations. By choosing appropriate metal layers (Al, Ag, Au) with optimized thickness ranges, the design achieves high durability and spectral performance while remaining compatible with conventional fabrication processes and tolerances

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 metal mirror-based multispectral filter array enhances durability and spectral capture accuracy by minimizing angle shift and expanding the spectral range, facilitating effective multispectral sensing without the integration difficulties of other filter types.

Implementation Method 1

a first mirror (110-1) and a second mirror (110-2) of a multispectral filter (105), wherein the first mirror (110-1) and the second mirror (110-2) each are or include a metal-based mirror

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 2

a first dielectric spacer layer (130-1) disposed between the first mirror (110-1) and the second mirror (110-2)

Methodology Applied
Scientific EffectRefraction: Refraction

Data Source

PatentEP3187909B1Metal mirror based multispectral filter array
Publication Date: 2026.02.11 VIAVI SOLUTIONS INC(US)
  • EP3187909B1 patent drawingFigure 1
  • EP3187909B1 patent drawingFigure 2
  • EP3187909B1 patent drawingFigure 3A

AI summary

A device may include a multispectral filter array disposed on the substrate. The multispectral filter array may include a first metal mirror disposed on the substrate. The multispectral filter may include a spacer disposed on the first metal mirror. The spacer may include a set of layers. The spacer may include a second metal mirror disposed on the spacer. The second metal mirror may be aligned with two or more sensor elements of a set of sensor elements.