Uniform 2D Target Generation via Inverse-designed Metasurfaces.

Area of Science:

• Optics and Photonics
• Computational Electromagnetics
• Materials Science

Background:

• Metasurfaces offer precise control over light wavefronts.
• Achieving uniform intensity profiles with arbitrary shapes remains a challenge.
• Existing methods often struggle with uniformity and efficiency.

Purpose of the Study:

• To develop an inverse design framework for metasurfaces.
• To achieve highly uniform 2D intensity profiles across on-demand shapes.
• To enhance projection efficiency and suppress field amplitude deviations.

Main Methods:

• Adjoint method for optimization objective.
• Regularization term to penalize intensity non-uniformity.
• Adaptive tuning of regularization weight.
• Finite Element Method (FEM) for surrogate modeling.
• Finite-Difference Time-Domain (FDTD) simulations for verification.

Main Results:

• Superior performance in intensity fidelity and uniformity compared to Mean Squared Error (MSE).
• Stable and efficient optimization process.
• Framework extended to handle Gaussian beam illumination.
• Demonstrated generation of high-quality, uniform field patterns.

Conclusions:

• The proposed inverse design framework effectively generates uniform 2D intensity profiles on metasurfaces.
• The adaptive regularization strategy ensures stable and efficient optimization.
• The method shows significant improvements over conventional approaches for metasurface design.