Graphene Light Source for Low-Etendue High-Temperature Fiber Sensing

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Solution Overview

Problem

Fiber optic sensors face inefficiencies and reliability issues in high-temperature environments, such as those exceeding 150 degrees Celsius, due to the degradation of light sources like laser diodes and LEDs, which affect light intensity and etendue, limiting their ability to effectively measure properties like pressure, temperature, and strain.

Innovation Solution

A fiber optic sensor system utilizing a graphene light source with low etendue, capable of maintaining light intensity and efficiency at high temperatures, incorporating a graphene filament as the light source that operates effectively above 150 degrees Celsius and features a nanophotonic interference filter to enhance light output within a specific wavelength band.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If conventional light sources like laser diodes and LEDs are used in high-temperature environments, then the sensor can operate in elevated temperature conditions, but the light intensity and etendue degrade, reducing measurement effectiveness

Engineering Contradiction:
Improveoperating temperatureVSAvoidlight source performance
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The patent changes the fundamental material parameter of the light source from conventional semiconductors (laser diodes and LEDs) to graphene. This material parameter change enables the light source to maintain stable performance at high temperatures exceeding 150°C, where conventional light sources would degrade. The graphene-based light source exhibits superior thermal stability, preserving both light intensity and etendue characteristics in high-temperature environments, thus resolving the contradiction between operating temperature and light source reliability.

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If conventional light sources are used, then the device structure remains simple and well-understood, but the etendue increases and light intensity decreases at high temperatures, limiting sensing effectiveness

Engineering Contradiction:
Improvelight source structureVSAvoidlight intensity
Core Design Contradiction:
Device complexityVSIllumination intensity

Solution Approach 1:

The patent applies parameter changes by transitioning from conventional semiconductor light sources to a graphene-based light source. This material substitution fundamentally alters the thermal and optical parameters of the light source. The graphene-based light source maintains low etendue and high light intensity even at temperatures exceeding 150°C, where conventional sources would fail. The nanophotonic interference filter further optimizes the optical parameters by enhancing light output within specific wavelength bands, ensuring effective sensing performance without compromising device simplicity.

Inventive Principle:
Principle #35Parameter changes

3Temperature

If the light source operates at high temperatures, then the sensor can measure properties in high-temperature environments, but the etendue increases reducing coupling efficiency into the optical fiber

Engineering Contradiction:
Improveenvironmental temperatureVSAvoidetendue
Core Design Contradiction:
TemperatureVSArea of stationary object

Solution Approach 1:

The patent resolves this contradiction by changing the material parameter of the light source to graphene, which inherently maintains low etendue characteristics under high-temperature conditions. The graphene-based light source exhibits stable optical parameters including low etendue even when operating at temperatures exceeding 150°C. Additionally, the nanophotonic interference filter is integrated to precisely control and optimize the spatial and angular distribution of emitted light, ensuring minimal etendue and maximum coupling efficiency into the optical fiber core, thus enabling effective high-temperature environmental sensing.

Inventive Principle:
Principle #35Parameter changes

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 graphene-based fiber optic sensor system ensures reliable and efficient measurement capabilities in high-temperature environments by maintaining light intensity and reducing etendue, enabling distributed sensing and spectroscopy over extensive lengths of fiber with improved reliability and operational longevity.

Implementation Method 1

A fiber optic sensor system utilizes a graphene light source with low etendue, capable of maintaining light intensity and efficiency at high temperatures

Methodology Applied
Scientific EffectElectroluminescence: Electroluminescence

Implementation Method 2

features a nanophotonic interference filter to enhance light output within a specific wavelength band

Methodology Applied
Scientific EffectInterference: Interference

Data Source

PatentEP3430379B1Low etendue light source for fiber optic sensors in high temperature environments
Publication Date: 2023.09.20 BAKER HUGHES CO
  • EP3430379B1 patent drawingFigure 1
  • EP3430379B1 patent drawingFigure 2
  • EP3430379B1 patent drawingFigure 3

AI summary

A fiber optic sensor to determine a property in an environment with a temperature exceeding 150 degrees Celsius includes a light source to emit broadband light, an etendue of the light source being less than 1000 square micro meter-steradians (m2 sr), and an optical fiber to carry incident light based on the broadband light and a reflection resulting from the incident light. A photodetector detects a resultant light based on the reflection and outputs an electrical signal, and a processor processes the electrical signal from the photodetector to determine the property.