Two-scale homogenization to determine effective parameters of thin metallic-structured films

Area of Science:

• Physics
• Electromagnetism
• Materials Science

Background:

• Thin films exhibit unique electromagnetic properties.
• Modeling interfaces in thin films is crucial for device applications.
• Existing models may not capture the behavior of very thin structures accurately.

Purpose of the Study:

• To develop a homogenization method for deriving effective transmission conditions in thin structured films.
• To establish an interface model with effective parameters for electromagnetic wave propagation.
• To validate the model's accuracy against full-wave simulations.

Main Methods:

• Matched asymptotic expansion technique for homogenization.
• Derivation of effective interface parameters and jump/boundary conditions.
• Application to metallic inclusions with Neumann or Dirichlet conditions for wave polarization.

Main Results:

• Unambiguous derivation of effective interface parameters.
• A validated model for thin interfaces up to near-wavelength thicknesses.
• Comparison with transmission line theory and generalized sheet transition conditions.

Conclusions:

• The proposed homogenization method provides accurate effective transmission conditions for thin films.
• The derived interface model is effective for electromagnetic wave propagation in thin structures.
• The method offers a robust alternative to existing models for thin film analysis.