Adjoint variable method for two-dimensional plasmonic structures.

Area of Science:

• Electromagnetics and Materials Science
• Computational Physics

Background:

• Sensitivity analysis is crucial for optimizing material designs.
• Existing methods like finite difference are computationally expensive, especially for wideband analysis.
• Dispersive materials require specialized techniques for accurate modeling.

Purpose of the Study:

• To develop a novel and efficient method for wideband sensitivity analysis of dispersive materials.
• To enable accurate calculation of sensitivities with respect to design parameters.
• To reduce the computational cost associated with sensitivity analysis.

Main Methods:

• Adjoint Variable Method (AVM) for sensitivity analysis.
• Time-domain transmission line modeling (TLM) for response calculation.
• Z-domain representation for modeling dispersive materials.

Main Results:

• The proposed AVM provides accurate wideband sensitivities for dispersive materials.
• The method requires at most one extra simulation, significantly reducing computational cost.
• Validation against the finite difference approach shows good agreement.

Conclusions:

• The developed AVM is a highly efficient and accurate technique for sensitivity analysis of dispersive materials.
• This method can be extended to various dispersive materials and metamaterials.
• The approach facilitates faster design and optimization of plasmonic devices and other electromagnetic structures.