Thermodynamic Limits of Spatial Resolution in Active Thermography

Area of Science:

• Physics
• Thermodynamics
• Statistical Mechanics

Background:

• Thermal waves, governed by diffusion, exhibit limited spatial resolution due to amplitude decay.
• Reconstructing subsurface structures from surface temperature measurements involves solving an ill-conditioned inverse problem.

Purpose of the Study:

• To develop a novel method for reconstructing embedded structures using thermal waves.
• To solve the inverse problem without additional assumptions or regularization parameters.

Main Methods:

• Application of non-equilibrium statistical physics methods.
• Utilizing the diffusion equation with a delta-source at a specific depth.
• Equating entropy production from thermal diffusion with information loss.

Main Results:

• Achieved structure reconstruction without regularization parameters or prior assumptions.
• Resolution is proportional to depth and inversely proportional to the natural logarithm of the signal-to-noise ratio.
• Derived results from fundamental physics principles without specific stochastic models.

Conclusions:

• Non-equilibrium statistical physics offers a robust framework for thermal wave imaging.
• The derived resolution limit provides a new benchmark for thermal wave microscopy.
• This method enhances the capability to image and characterize subsurface structures with improved accuracy.