Phys.org October 15, 2024
Janus metasurfaces have the ability to control light asymmetrically at the pixel level within thin films. However, previous demonstrations are restricted to the partial control of asymmetric transmission for a limited set of input polarizations, focusing primarily on scalar functionalities. Researchers in the Republic of South Korea developed optical bi-layer metasurfaces that achieve a fully generalized form of asymmetric transmission for any input polarization. The theoretical model revealed a fundamental correlation between the polarization-direction channels of opposing sides. They partitioned the transmission space to realize four distinct vector functionalities within the target volume. As a proof of concept, they demonstrated polarization-direction-multiplexed Janus vectorial holograms generating four vectorial holographic images. When integrated with computational vector polarizer arrays, their approach enabled optical encryption with a high level of obscurity. According to the researchers their framework and novel material systems for generalized asymmetric transmission may pave the way for applications such as optical computation, sensing, and imaging… read more. Open Access TECHNICAL ARTICLEÂ
Schematics of a device featuring asymmetric transmission… Credit: Advanced Materials, 13 September 2024