Internal temperature inversion in semi-transparent materials based on spectral radiative transfer modeling.

Area of Science:

• Physics
• Materials Science
• Thermodynamics

Background:

• Non-contact temperature measurement in semi-transparent materials is difficult due to optical properties and thermal gradients.
• Conventional infrared thermometry struggles with complex media, limiting thermal profiling accuracy.

Purpose of the Study:

• To develop an advanced spectral inversion model for precise non-contact temperature measurement in semi-transparent multilayer materials.
• To overcome limitations posed by optical inhomogeneities and depth-dependent thermal gradients.

Main Methods:

• Utilized a spectral inversion model based on the scattering matrix and fluctuation-dissipation theorem.
• Integrated simulated annealing algorithm with local ensemble averaging for high-precision temperature reconstruction.
• Validated the model through numerical simulations on five-layer thin-film structures with varying optical constants.

Main Results:

• Achieved high-precision reconstruction of internal temperature distribution in multilayer materials.
• Demonstrated robust performance under multiplicative uniform noise (0.5%-5%), with max relative errors below 0.67% at 5% noise.
• Successfully reconstructed temperature distributions in complex thin-film structures.

Conclusions:

• The proposed spectral inversion framework provides an accurate non-contact method for thermal profiling in challenging semi-transparent materials.
• This approach is suitable for complex media where conventional infrared thermometry is insufficient.
• Offers a significant advancement in non-contact thermal metrology for materials science and engineering.