Multispectral Reflection Imaging Device With Oblique Waveguide

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Solution Overview

Problem

Existing multispectral imaging technologies for biological samples are time-consuming, complex, expensive, and bulky, and multispectral IR imaging in transmission does not allow for effective biochemical mapping of thick samples due to water absorption, while reflection IR spectrometry methods suffer from low penetration and require complex deflector networks or excessive light absorption.

Innovation Solution

A multispectral reflection imaging device with a light deflection device that uses oblique and flat portions on a material portion to deflect light and collect backscattered light, allowing for efficient imaging with a large spectral band and reduced bulk, using a photonic integrated circuit (PIC) design with a light deflection device inserted between the imager and the sample.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If reflection IR spectrometry using ATR is used to overcome water absorption, then biochemical mapping of thick samples is enabled, but the field of view is limited and the measuring system must be placed as close as possible to the sample

Engineering Contradiction:
Improvebiochemical mapping capabilityVSAvoidfield of view
Core Design Contradiction:
ReliabilityVSArea of stationary object

Solution Approach 1:

The patent transitions from the conventional ATR configuration where the measuring system is placed close to the sample surface to a remote configuration using optical waveguides. The light deflection device redirects light paths in three-dimensional space, enabling the measuring system to be positioned at a distance while maintaining effective interaction with the sample through total internal reflection at the waveguide-sample interface.

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

2Area of stationary object

If a matrix of deflector networks is used to expand field of view, then imaging area is increased, but the construction becomes complex and bolometers are masked

Engineering Contradiction:
Improveimaging areaVSAvoidconstruction complexity
Core Design Contradiction:
Area of stationary objectVSDevice complexity

Solution Approach 1:

The patent extracts the light deflection function from complex planar deflector networks and implements it through simple geometric features on the waveguide surfaces. The oblique faces and planar portions on the waveguide provide the necessary light redirection without requiring complex deflector networks, thereby reducing construction complexity while maintaining imaging area.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces an optical waveguide as an intermediary element between the light source and the sample. This waveguide mediates the light transport, allowing light to be delivered to and collected from the sample without requiring complex deflector networks at the detector plane, thus simplifying the overall system construction.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of operation

If an etched silicon substrate chip is used to inject laser beams, then light injection is achieved, but the chip size is large and light absorption by silicon is excessive

Engineering Contradiction:
Improvelight injection capabilityVSAvoidlight absorption
Core Design Contradiction:
Ease of operationVSLoss of energy

Solution Approach 1:

The patent changes the material parameter from silicon to materials with lower absorption coefficients in the infrared range, such as diamond, sapphire, or zinc selenide. This parameter change reduces light absorption losses while maintaining the light injection capability through the waveguide structure.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces the complex mechanical light injection system requiring large etched silicon chips with an optical waveguide system that guides light through total internal reflection. This substitution eliminates the need for large substrate chips and complex injection mechanisms while reducing light absorption.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

4Device complexity

If quantum cascade lasers are used to produce monochromatic IR sources, then spectral analysis is simplified, but multiple sources are required to cover the full spectral range

Engineering Contradiction:
Improvespectral analysis complexityVSAvoidnumber of light sources
Core Design Contradiction:
Device complexityVSQuantity of substance

Solution Approach 1:

The patent makes the optical waveguide system universal by designing it to work with multiple QCL sources covering different spectral ranges. The waveguide structure and light deflection device are configured to handle various wavelengths, allowing a single system to perform multispectral imaging using multiple monochromatic sources without requiring separate analysis systems for each wavelength.

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 device achieves efficient imaging with a large field of view and spatial resolution, guiding wavelengths in the mid-infrared range, uniformly illuminating a surface area greater than 2.5 mm², and collecting photons reflected by the object, while being thermally stable and less complex to produce.

Implementation Method 1

one of the first and second main faces being provided with portions oblique to the other of the first and second main faces and each configured to deflect a portion of the light received towards the sample

Methodology Applied
Scientific EffectTotal internal reflection: Total Internal Reflection

Implementation Method 2

planar portions parallel to the other of the first and second main faces and configured to allow the light backscattered by the sample to pass

Methodology Applied
Scientific EffectLight transmission:

Implementation Method 3

A multispectral reflection imaging device with a light deflection device that uses oblique and flat portions on a material portion to deflect light and collect backscattered light

Methodology Applied
Scientific EffectWaveguide: Waveguide (optics)

Data Source

PatentEP4345446B1Device for multispectral imaging in reflection
Publication Date: 2025.05.21 COMMISSARIAT A LENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES
  • EP4345446B1 patent drawingFigure 1~3
  • EP4345446B1 patent drawingFigure 4~6
  • EP4345446B1 patent drawingFigure 7

AI summary

Imaging device (100) configured to image a sample (102), comprising: - a light source (104) emitting light; - a light deflection device configured to deflect the light emitted by the light source towards the sample, comprising a portion of material (106) having a first main face (108) disposed opposite the sample (102), a second main face (110), and a first lateral face (112) towards which the light is emitted by the light source; - an imager (118) having a detection face (122) disposed opposite the second main face and intended to receive the light backscattered by the sample;in which one of the principal faces has oblique parts (114) each configured to deflect a portion of the received light towards the sample (102), and flat parts (116) configured to allow the light backscattered by the sample to pass through, and in which each pixel (120) of the imager (118) is arranged opposite one of the flat parts (116) of said one of the first and second principal faces (108, 110).;