Planar Waveguide Optical Component for ATR Interferometric Imaging

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Solution Overview

Problem

Attenuated Total Reflection Imaging (ATR) techniques face challenges in distinguishing between highly absorbing and weakly absorbing compounds in a sample, as absorption by highly absorbent compounds masks the absorption by weakly absorbent compounds, making direct absorption measurements unsuitable.

Innovation Solution

An optical component comprising a planar waveguide with inclined input and output facets that separate an initial light beam into object and reference beams, allowing for interferometry and phase measurement-based imaging, enabling the formation of interferometric images by attenuated total reflection without the complexity of multiple optical components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If direct absorption measurements are used in ATR imaging, then highly absorbing compounds can be detected, but the absorption by weakly absorbing compounds is masked and cannot be distinguished

Engineering Contradiction:
Improvedetection of highly absorbing compoundsVSAvoidabsorption information of weakly absorbing compounds
Core Design Contradiction:
Measurement precisionVSLoss of information

Solution Approach 1:

The invention changes the measurement parameter from direct absorption to phase shift. By measuring the phase shift of light rather than direct absorption, the system can detect both highly absorbing and weakly absorbing compounds simultaneously, as phase shift measurements are not dominated by the strong absorption signals that mask weaker ones.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention introduces an interferometric measurement system as an intermediary between the light and the sample. The Mach-Zehnder interferometer configuration allows phase shift information to be extracted indirectly through interference patterns, enabling detection of weakly absorbing compounds that would otherwise be masked.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If interferometric imaging with multiple optical components is used to avoid absorption masking, then phase measurements can be obtained, but the device complexity increases significantly

Engineering Contradiction:
Improvephase measurement capabilityVSAvoidnumber of optical components
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The invention merges multiple optical functions into a single integrated planar waveguide component. The waveguide incorporates both the interferometric path separation and the ATR measurement interface, eliminating the need for multiple discrete optical components while maintaining phase measurement capability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The planar waveguide serves multiple functions simultaneously: it acts as the interferometric path separator, the ATR prism interface, and the sample holder. This multi-functional design reduces device complexity while preserving the phase measurement capability needed to distinguish weakly absorbing compounds.

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

This solution allows for the determination of chemical or biological compositions in samples, even when highly absorbing compounds are present, by exploiting phase shifts and interference patterns, providing a simpler and robust means for multi-spectral imaging.

Implementation Method 1

two inlet facets formed in the planar waveguide, said inlet facets being inclined at an angle relative to the plane of the front and rear faces of the planar waveguide... configured together to separate an initial light beam into two sub-beams

Methodology Applied
Scientific EffectRefraction: Refraction

Implementation Method 2

Attenuated total reflection imaging (ATR)... light is directed into a prism placed against a sample to be analyzed. The light is entirely reflected at an interface between the prism and the sample

Methodology Applied
Scientific EffectTotal internal reflection: Total Internal Reflection

Implementation Method 3

The optical component is configured so that the two sub-beams can interfere with each other after emerging from the planar waveguide

Methodology Applied
Scientific EffectInterference: Interference

Data Source

PatentEP4016055B1Optical component for an atr imaging interferometric device
Publication Date: 2023.09.27 COMMISSARIAT A LENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES
  • EP4016055B1 patent drawingFigure 1~2C
  • EP4016055B1 patent drawingFigure 2D~4
  • EP4016055B1 patent drawingFigure 5A~6

AI summary

Optical component (100) for an attenuated total reflection imaging interferometric device, comprising: - a planar waveguide (110), delimited in particular by a front face (112) and a rear face (111) parallel to each other; - an injection zone (120), comprising two entrance facets (121, 122), each extending from a lateral face (113) of the planar waveguide, configured to separate an initial light beam into two sub-beams each deflected in a respective direction upon their entry into the planar waveguide; and - an extraction zone (130), comprising two exit facets (131, 132), configured to receive the two subbeams, and to deflect the latter at their exit out of the planar waveguide, the optical component (100) being configured so that the two subbeams (102A, 102B) can interfere with each other after emerging out of the planar waveguide.