Optical Fiber Temperature Measurement via Fluorescence
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Direct temperature measurement of optical fibers during fusion processes is challenging due to the need for precise heat control and the difficulty in distinguishing fiber temperature from the heat source without disrupting the process, especially in high-temperature environments.
Innovation Solution
An indirect method using fluorescence emission from doping molecules within the optical fibers, calculating the temperature ratio of adjacent emission lines to deduce the population distribution based on Boltzmann distribution, enabling remote temperature measurement up to 2000°C.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If direct contact measurement is used to measure fiber temperature, then temperature data can be obtained, but the measurement disturbs the fusion process
Solution Approach 1:
The patent uses fluorescence emission from dopant molecules as an intermediary to indirectly measure fiber temperature. Instead of direct contact measurement that disturbs the fusion process, the method detects optical signals (fluorescence) emitted by the fiber itself when heated, allowing temperature determination without physical contact or interference with the fusion process
2Reliability
If non-contact measurement is used to distinguish fiber temperature from heat source, then the fusion process is not disturbed, but it is very difficult to distinguish between fiber temperature and heat source temperature
Solution Approach 1:
The patent exploits the local quality of fluorescence emission that occurs specifically within the fiber core where dopant molecules are concentrated. By detecting the characteristic fluorescence spectrum from these dopant molecules (such as OH- ions), the measurement specifically reflects the local temperature of the fiber material rather than the broader heat source temperature, enabling precise differentiation between fiber and heat source temperatures
Solution Approach 2:
The method utilizes changes in the optical spectrum (color/ wavelength distribution) of fluorescence emission to determine temperature. By analyzing the spectral characteristics and intensity ratios of different fluorescence emission lines, the fiber temperature can be precisely measured without being affected by the heat source temperature, as the fluorescence spectrum provides a direct optical signature of the fiber's thermal state
3Reliability
If fluorescence emission from dopant molecules is used for temperature measurement, then remote non-invasive measurement is enabled, but requires precise calculation of population distribution based on Boltzmann distribution
Solution Approach 1:
The patent transforms the complex Boltzmann distribution calculation into a practical measurement by changing the approach to using easily measurable optical parameters. By measuring the intensity ratio of two specific fluorescence emission lines with known energy level differences, the temperature can be calculated using a simplified relationship derived from Boltzmann statistics, avoiding the need for complex population distribution calculations while maintaining accuracy
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
Enables precise, non-invasive, and remote temperature measurement of optical fibers during high-temperature fusion processes, providing accurate temperature data for controlling heat absorption and ensuring process precision.
Implementation Method 1
heating an optical fiber to induce fluorescence emission from the optical fiber
Implementation Method 2
By calculating the ratio between the powers of two adjacent emission lines the population distribution between energy levels can be deduced. Since the population is temperature dependence via Boltzmann distribution, the temperature of the fiber can be concluded.
Data Source
AI summary
A method for temperature measurement includes measuring intensities of two adjacent wavelengths emitted from a heated optical fiber and calculating the thermal population distribution between associated energy levels. The optical fiber is heated to induce fluorescence emission from the optical fiber. The optical fiber comprises OH− dopant ions. The fluorescence emission is due to a first overtone of vibration energy level of the OH− dopant ions.