Nano-channel Optical Waveguide for Low-Loss Fluid Analysis

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Solution Overview

Problem

Current optical waveguides face challenges in achieving low loss and long interaction lengths for fluids with low molar extinction coefficients, are prone to radiation losses due to curvature, and have difficulties in manufacturing long lengths without damaging the core layer.

Innovation Solution

A nano-channel optical waveguide design featuring two substrates with optical guiding structures facing each other, a channel between them, and laterally attached tanks to minimize radiation losses and facilitate fluid circulation, allowing for long lengths with reduced footprint and improved fluid flow.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the optical waveguide is made longer to increase interaction length, then sensitivity is improved, but radiation losses increase due to curvature

Engineering Contradiction:
ImprovesensitivityVSAvoidradiation losses
Core Design Contradiction:
Measurement precisionVSLoss of energy

Solution Approach 1:

The optical waveguide is divided into multiple straight sections separated by bends, with each section having optimized dimensions to minimize radiation losses while maintaining overall length for sufficient interaction

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The waveguide transitions from a simple linear configuration to a multi-dimensional folded structure, increasing the interaction length in the fluid direction while keeping the footprint compact and reducing curvature-induced losses through optimized bending geometry

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

2Length of stationary object

If the waveguide length is increased to several tens of centimeters or meters, then interaction length is improved, but manufacturing difficulty increases due to damage risk to core layer

Engineering Contradiction:
Improvewaveguide lengthVSAvoidmanufacturing difficulty
Core Design Contradiction:
Length of stationary objectVSEase of manufacture

Solution Approach 1:

The long waveguide is segmented into multiple sections that can be manufactured separately and then assembled, reducing the risk of damage to the core layer during manufacturing while achieving the required overall length

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different sections of the waveguide have locally optimized dimensions and properties to minimize radiation losses and prevent fluid blockage, with the core layer protected from damage through careful design of each section

Inventive Principle:
Principle #3Local quality

3Adaptability or versatility

If the slot is emptied to allow fluid introduction, then fluid analysis capability is improved, but manufacturing complexity increases due to difficulty in eliminating material without damaging core layer

Engineering Contradiction:
Improvefluid analysis capabilityVSAvoidmanufacturing complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The waveguide structure is segmented to create discrete channels between the core layer and the fluid interface, allowing fluid introduction without requiring complete material removal, thus simplifying manufacturing while maintaining fluid analysis capability

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

An intermediary structure is introduced between the core layer and the fluid to enable fluid interaction with the optical mode while protecting the core layer from direct contact and damage during manufacturing

Inventive Principle:
Principle #24Intermediary (Mediator)

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 design achieves lower radiation losses, enables longer interaction lengths, and prevents fluid blockage or damage, enhancing sensitivity and operational stability for fluid analysis.

Implementation Method 1

The optical waveguide comprises a base substrate (1) surmounted by a core (2) which takes the form of two parallel rails (2.1, 2.2)

Methodology Applied
Scientific EffectTotal internal reflection: Total Internal Reflection

Implementation Method 2

Absorption spectrometry is based on the ability of chemical species to absorb light at certain wavelengths. It is described by the Beer-Lambert law which is expressed by P=P0 exp(-αL)

Methodology Applied
Scientific EffectAbsorption spectrometry: Absorption (EM radiation)

Data Source

PatentEP2925443B1Optical waveguide comprising a nano-channel and optofluidic sensor using such an optical waveguide
Publication Date: 2017.05.10 COMMISSARIAT A LENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES
  • EP2925443B1 patent drawingFigure 1~2C
  • EP2925443B1 patent drawingFigure 3A~3D
  • EP2925443B1 patent drawingFigure 4~5C

AI summary

It is a question of an optical waveguide comprising a first substrate (10) incorporating a first optical guiding structure (12) exposed on the surface (11) of the first substrate (10), and a second substrate (20) incorporating a second optical guiding structure (22) exposed on the surface (21) of the second substrate (20), these two substrates (10, 20) being assembled superposed via their surfaces (11, 21) so that the two optical guiding structures (12, 22) are arranged opposite each other and extend in the same direction, a channel (30) being provided between the first and second guiding structure (12, 22), this channel (30) being directed along said direction and having a cross section a large dimension of which is substantially parallel to the surface (11) of the first substrate (10) and to the surface (22) of the second substrate (20), allowing light to interact over a given distance with the fluid. Application especially to the analysis of fluids.