Phys.org February 2, 2022
Metamaterials can be engineered to produce desired interactions with light or sound waves. However, functionality of the devices can be limited by the corresponding design space. A team of researchers in the US (Pennsylvania State University, Sandia National Laboratory) leveraged a combination of a genetic algorithm (GA) based optimization method and a membrane projection lithography (MPL) fabrication approach, to demonstrate a quasi-3D metamaterial for broadband asymmetric transmission (AT) of linearly polarized mid-infrared light. An efficient exploration of 3D plasmonic meta-atoms with broken mirror symmetry in the light propagation direction allows the satisfaction of the rigorous conditions for AT of linearly polarized waves over a broad wavelength range. They attributed the AT behavior to the resonant coupling between the plasmonic nanostructures located on the two orthogonal walls of the MPL cavities. According to the researchers their methodology provides a promising route for exploiting 3D metamaterials with sophisticated functionalities… read more. TECHNICAL ARTICLEÂ
Rsearchers optimized and fabricated this design for a metamaterial building block that could enable more efficient optical devices. Credit: Lei Kang