Macroscopic wave-optical simulation of dielectric metasurfaces

Area of Science:

• Optics and Photonics
• Computational Electromagnetics
• Nanophotonics

Background:

• Current diffractive optical element (DOE) simulation methods often rely on local periodicity assumptions, limiting accuracy.
• Simulating complex DOEs like metasurfaces requires efficient and accurate computational techniques.
• Existing methods may struggle with non-periodic structures and require significant computational resources.

Purpose of the Study:

• To introduce a novel wave-optical simulation method for diffractive optical elements (DOEs).
• To enable semi-rigorous simulation of entire DOEs, including metasurfaces and computer-generated holograms (CGHs).
• To provide a computationally efficient alternative to existing simulation techniques.

Main Methods:

• A specially adapted finite-difference beam propagation method (BPM) is utilized.
• The method employs linear scaling with the number of grid points for runtime efficiency.
• The simulation approach is semi-rigorous, offering a balance between accuracy and speed.

Main Results:

• The novel BPM method allows for the simulation of entire DOEs within reasonable runtimes.
• Demonstrated applicability through the simulation of a metalens and a polarization-dependent beamsplitter.
• Simulations showed high conformity when compared to rigorous electromagnetic simulations.

Conclusions:

• The proposed finite-difference beam propagation method (BPM) offers an efficient and accurate approach for simulating diffractive optical elements (DOEs).
• This method is suitable for complex nanophotonic devices like metalenses and polarization-dependent beamsplitters.
• The technique provides a viable alternative for researchers and engineers working with metasurfaces and CGHs.