[论文解读] Temperature in Glass Slides: measurement using Phase Sensitive Optical Coherence Tomography and Computational Modeling

José M. Folgueiras, L. G. Chej+5 more|arXiv (Cornell University)|Mar 18, 2026

Optical Coherence Tomography Applications被引用 0

一句话总结

论文展示了一种相位敏感光学相干断层成像（PhS-OCT）方法，采用共路路径设置测量在1毫米苏打石灰玻璃片中随温度变化的光学路径差（OPD），在20–52°C标定，理论与数值建模验证该方法。

ABSTRACT

Phase-sensitive optical coherence tomography (PhS-OCT) enables precise, contactless measurements of temperature-dependent changes in transparent solids. In this work, we used a common-path spectral-domain OCT system to measure optical path differences (OPD) in a 1-mm-thick soda-lime glass slide immersed in a thermal bath. The OPD variation showed a strong linear correlation with temperature in the range of 20-52°C, with an experimentally determined sensitivity of 12.4 +- 1.9 nm/°C. A theoretical model incorporating the thermo-optic and thermal expansion coefficients of glass was proposed to interpret the measurements, and numerical simulations based on finite volume methods were performed to account for spatial temperature gradients in the system. The simulations showed agreement with experimental results within 5% error, validating the approach. Additionally, repeatability tests using lateral scans at constant temperature demonstrated sub-10 nm stability, supporting future extensions to spatially resolved thermal mapping. This technique provides a low-cost platform for localized temperature sensing in solid transparent materials.

研究动机与目标

• Develop a contactless method to measure temperature inside a solid transparent material using PhS-OCT.
• Establish a calibrated OPD–temperature relationship for a soda-lime glass slide in a controlled bath.
• Provide uncertainty quantification and assess repeatability and potential for spatial thermal mapping.
• Validate experimental measurements with a thermo-mechanical–optical model and finite-volume thermal simulations.

提出的方法

• Use a common-path FD-OCT system where both surfaces of a glass slide form sample and reference arms.
• Calibrate OPD versus temperature across 20–50°C using controlled thermal bath experiments.
• Retrieve phase from multiple points within the Maximum Amplitude Zone to improve accuracy and avoid phase-wrapping artifacts.
• Model OPD changes as Δz ≈ L( dn/dT + β n ) ΔT with material-specific dn/dT and β, and compare with experimental slopes.
• Perform 3D OpenFOAM-based conjugate heat transfer simulations to map temperature distribution and validate sensor readings.
• Quantify measurement uncertainty including OPD repeatability and slope uncertainty.

Figure 1: Schematic of the low-coherence interferometer setup. Key components: (a) SuperK white-light laser, (b) 50:50 fiber beam splitter, (c) collimator (d) HR4000 spectrometer.

实验结果

研究问题

• RQ1 Can phase-sensitive OCT provide reliable, contactless temperature measurements inside a solid glass substrate?
• RQ2 What is the calibrated OPD–temperature relationship for soda-lime glass in the 20–50°C range, and how well does theory match experiment?
• RQ3 How uniform is the temperature in the water bath around the glass slide, and how does this affect OPD-based thermometry?
• RQ4 What are the repeatability and spatial profiling capabilities of the proposed method for potential 2D thermal mapping?

主要发现

• OPD shows a strong linear correlation with temperature in 20–52°C with sensitivity 12.4 ± 1.9 nm/°C.
• Measured OPD–temperature slope agrees with theoretical prediction (~13.5 nm/°C) within ~8.5%.
• R² > 0.99 for all measurement series, demonstrating robust linearity between OPD and temperature.
• MAPE between experimental and simulated temperatures is 4.97% across series S3 and S4.
• Sub-10 nm repeatability in spatial OPD profiling enables potential detection of thermal gradients.
• OPD-based temperature measurement achieves a low-cost, label-free approach suitable for localized thermal sensing in transparent solids.

Figure 2: Cross-sectional view of the temperature-controlled water bath assembly: (c) collimator (e) glass crystallizer, (f) glass slide, (g) plastic tube maintaining dry optical surface, (h) ceramic hot plate with PID controller, and (i) PT100 thermal sensor.