Modelling the propagation of terahertz radiation through a tissue simulating phantom

Area of Science:

• Biomedical Imaging
• Computational Electromagnetics
• Terahertz Science

Background:

• Terahertz (THz) frequency radiation (0.1–20 THz) shows promise for biomedical imaging.
• Pulsed THz sources enable spectral and temporal information extraction for sensor development.

Purpose of the Study:

• To develop and evaluate computational models for interpreting broadband THz spectra.
• To compare deterministic and stochastic approaches for simulating THz radiation propagation in absorbing media.

Main Methods:

• Developed and compared a thin film analysis model and a stochastic Monte Carlo model.
• Utilized the Cole-Cole model to predict frequency-dependent physical properties.
• Neglected scattering effects in the initial models.
• Validated models against measurements from a water-based phantom.

Main Results:

• The Monte Carlo model yielded predictions closer to experimental results in the 0.1 to 3 THz range.
• Accurate knowledge of frequency-dependent physical properties, including scattering, is crucial for THz imaging.
• The thin film model is computationally simple but limited by sample geometry.
• The Monte Carlo model offers greater flexibility for complex sample geometries.

Conclusions:

• The Monte Carlo model is a more accurate tool for simulating THz propagation in biomedical applications.
• Further research needs to incorporate scattering characteristics for enhanced model fidelity.
• Computational modeling is essential for advancing THz biomedical imaging and sensing technologies.