Spectroscopic Sensor Accuracy Assessment via Etalon Drift Simulation

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Solution Overview

Problem

Spectroscopic sensors, particularly on-chip TDLAS sensors, face accuracy issues due to optical fringing caused by light reflections, which are difficult to isolate and remove, leading to inaccurate analyte quantification and requiring frequent recalibration, especially under varying environmental conditions.

Innovation Solution

A method for assessing spectroscopic sensor accuracy involves building an a priori simulation of generalized etalon drift, determining use parameters, generating a specific drift model, and analyzing it to determine sensor suitability, allowing for quick and efficient characterization of etalon contributions and noise factors without the need for long-term measurements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional Allan-deviation analysis is used to determine sensor MDL and stability time, then accurate measurement is achieved, but testing time increases significantly and scalability is reduced

Engineering Contradiction:
Improvesensor accuracy assessmentVSAvoidtesting time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent creates a computational model that replicates the complex optical interference patterns and sensor responses, allowing virtual testing and analysis without requiring extensive physical measurements. This model-based approach preserves measurement accuracy while dramatically reducing the time required for sensor characterization.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent performs preliminary computational analysis to predict sensor behavior and identify key parameters before conducting physical measurements. By pre-characterizing the optical interference patterns and sensor responses through simulation, the actual measurement process is shortened while maintaining assessment accuracy.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If sensor recalibration is performed frequently to maintain accuracy, then measurement precision is maintained, but productivity decreases

Engineering Contradiction:
Improveanalyte quantification accuracyVSAvoidsensor operational efficiency
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent replaces physical recalibration procedures with computational correction methods. By using algorithms to model and compensate for drift effects in software, the system maintains measurement precision without requiring time-consuming physical recalibration operations, thereby improving operational efficiency.

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

3Device complexity

If on-chip spectroscopic sensors are used to improve integration, then device complexity is reduced, but optical fringing effects increase

Engineering Contradiction:
Improvesensor integration levelVSAvoidoptical fringing
Core Design Contradiction:
Device complexityVSObject-generated harmful factors

Solution Approach 1:

The patent transforms the harmful optical fringing effects into useful diagnostic information. By deliberately analyzing the interference patterns generated by on-chip sensors, the system characterizes sensor properties and drift behavior, converting what was previously a nuisance into a valuable measurement tool for monitoring and correction.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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 approach enables rapid assessment of sensor stability and sensitivity, reducing testing time by up to 103× and making it scalable for large-scale manufacturing, while ensuring only sensors with tolerable fringing levels are used, thereby improving accuracy and stability under various environmental conditions.

Implementation Method 1

Spectroscopic sensors may be used as part of laser absorption spectroscopy (LAS) techniques to determine the atomic and/or molecular composition of matter by analyzing the frequency spectrum of laser light passing through an analyte

Methodology Applied
Scientific EffectAbsorption Spectroscopy: Absorption Spectroscopy

Implementation Method 2

spectroscopic sensors such as on-chip TDLAS sensors may be prone to reflections of light from unwanted interfaces that may lead to various standing wave interference patterns

Methodology Applied
Scientific EffectOptical interference: Interference

Implementation Method 3

This effect may be known as optical fringing, or Fabry-Perot etalons, as it is caused by the light circulating within an unintended optical cavity of the spectroscopic sensor

Methodology Applied
Scientific EffectFabry-Perot etalon: Fabry-Perot Interferometer

Implementation Method 4

recent developments utilizing silicon photonic waveguides within the on-chip spectroscopic sensors may be particularly prone to optical fringes with difficult to predict time-dependent variations particularly due to ambient temperature fluctuations, owing to the relatively large thermo-optic coefficient of silicon

Methodology Applied
Scientific EffectThermo-optic effect:

Data Source

PatentUS11340110B2System and method for assessing spectroscopic sensor accuracy
Publication Date: 2022.05.24 INTERNATIONAL BUSINESS MACHINE CORPORATION
  • US11340110B2 patent drawing
  • US11340110B2 patent drawing
  • US11340110B2 patent drawing

AI summary

A method for assessing spectroscopic sensor accuracy, includes building an a priori simulation of generalized etalon drift. A spectroscopic sensor is tested to determine use parameters. A specific drift model is generated by applying the determined use parameters to the built a priori simulation of generalized etalon drift. The specific drift model is analyzed to determine whether the spectroscopic sensor is satisfactory.