Analysis and design of two-dimensional compound metallic metagratings using an analytical method

Area of Science:

• Electromagnetism
• Metamaterials
• Optics

Background:

• Metagratings offer efficient wavefront manipulation of electromagnetic (EM) waves.
• Existing methods for metagrating design can be complex and require extensive optimization.

Purpose of the Study:

• To propose a novel analytical method for diffraction analysis of 2D compound metallic metagratings.
• To demonstrate the design of efficient metagratings for specific EM wave manipulation tasks.

Main Methods:

• Development of closed-form analytical expressions for reflection coefficients of diffracted orders in 2D metagratings.
• Verification of the analytical method against full-wave simulations.
• Design of metagratings for specific applications without iterative optimization.

Main Results:

• The proposed analytical method accurately predicts diffraction behavior, showing excellent agreement with full-wave simulations.
• A perfect out-of-plane reflector and a five-channel beam splitter were designed with high power efficiency.
• The designed metagratings outperform previously reported structures in efficiency and error metrics.

Conclusions:

• 2D metagratings, designed with the proposed analytical method, offer a powerful and efficient way to control EM waves.
• This approach facilitates the development of advanced optical components across microwave to terahertz frequencies.
• The method simplifies metagrating design, enabling broader applications in EM wave manipulation.