Multi-pass Gas Cell with Integrated Curved Mirrors

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Solution Overview

Problem

Existing multi-pass gas cells face a tradeoff between increasing light absorption for detecting low gas concentrations and reducing throughput due to reflection losses, requiring multiple gas cells or variable path lengths, which increases complexity and cost.

Innovation Solution

A multi-pass gas cell design featuring integrated curved mirrors or lenses, including configurations with spherical, concave, or flat mirrors, allowing for multiple optical path lengths and compatibility with MEMS technology for miniaturization and mass production.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the number of passes is increased to detect low gas concentrations, then detection sensitivity is improved, but throughput decreases due to reflection losses

Engineering Contradiction:
Improvedetection sensitivityVSAvoidthroughput
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent combines multiple optical path lengths into a single gas cell by integrating multiple reflectors (first, second, and third reflectors) that create different light paths (first path length, second path length, third path length) within the same physical cell, allowing the system to achieve multiple detection sensitivities without requiring multiple separate gas cells

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent implements variable optical path length capability within a single gas cell by using reflectors that can direct light through different numbers of passes (1, 2, or 4 passes), enabling dynamic adjustment of the effective path length to optimize detection sensitivity for different gas concentration ranges while maintaining high throughput

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If multiple gas cells or variable path length cells are used to monitor different gases, then measurement versatility is improved, but device complexity and cost increase

Engineering Contradiction:
Improvemeasurement versatilityVSAvoiddevice complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent creates a universal gas cell that can measure multiple different gases with varying absorption characteristics by providing multiple optical path lengths (1, 2, or 4 passes) within a single cell structure, eliminating the need for multiple specialized gas cells and reducing overall system complexity

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges the functionality of multiple gas cells with different path lengths into a single integrated cell by using a shared enclosure and multiple reflectors that can be configured to create different optical paths, thereby reducing device complexity and cost while maintaining measurement versatility

Inventive Principle:
Principle #5Merging (Combining)

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 enhances detection capabilities for multiple gases with different absorption levels while maintaining high reflectivity and compatibility with MEMS spectrometers, reducing manufacturing complexity and cost.

Implementation Method 1

Some gas cells use a set of mirrors to reflect the light through multiple passes until the light exits the gas cell

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 2

A portion of the light will be absorbed by the gases, while the rest may be detected

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

Data Source

PatentEP3935369B1Compact multi-pass gas cell for multi-gas spectral sensors
Publication Date: 2023.01.11 SI WARE SYSTEMS INC(US)
  • EP3935369B1 patent drawingFigure 1
  • EP3935369B1 patent drawingFigure 2
  • EP3935369B1 patent drawingFigure 3

AI summary

Aspects of the disclosure relate to a multi-pass gas cell that includes a set of two or more reflectors, an input collimating optical component, and an output focusing optical component. The input and output optical components are integrated with at least one of the two or more reflectors. For example, the input and output optical components may be integrated on opposite ends of a single one of the reflectors or may be integrated on the same end of a single reflector. The input and output optical components may further be integrated with different reflectors. In some examples, the set of reflectors and optical components may be fabricated within the same substrate.