General finite-difference time-domain solution of an arbitrary electromagnetic source interaction with an arbitrary...

Area of Science:

• Computational Electromagnetics
• Nanophotonics
• Optical Detector Design

Background:

• Designing detector networks for surface-enhanced Raman scattering (SERS) requires accurate simulation tools.
• Simulating the interaction of electromagnetic beams with dielectric surfaces is a key challenge.

Purpose of the Study:

• To develop a numerical algorithm for calculating electromagnetic beam interactions with arbitrary dielectric surfaces.
• To enable the design and construction of SERS-based detector networks.

Main Methods:

• Utilized the scattered-field finite-difference time-domain (FDTD) method.
• Incorporated incident source terms into FDTD equations.
• Developed a novel scattered-field uniaxial perfectly matched layer (SF-UPML) absorbing boundary condition (ABC).

Main Results:

• The developed algorithm accurately calculates the interaction of arbitrary electromagnetic beams with arbitrary dielectric surfaces.
• The novel SF-UPML provides accurate truncation of the computational domain for the scattered-field FDTD grid.
• Numerical accuracy comparable to conventional methods for source-free FDTD equations is achieved.

Conclusions:

• The new scattered-field FDTD method with SF-UPML is a powerful tool for electromagnetic wave scattering calculations.
• This advancement facilitates the accurate modeling of scattering by dielectric surfaces and particles under arbitrary illumination.
• The developed algorithm is essential for the design of advanced SERS detector networks.