Phys.org September 30, 2024
In chiral metasurfaces, the lack of symmetry leads to differential absorption when probed with chiral light either in the form of circular polarization or helical phase fronts. Researchers in Canada demonstrated differential absorption of asymmetric twisted light beams, known as helical dichroism, which exist in an array and a single achiral structure and could be controlled. When extended to chiral structures, these asymmetrical chiral light modes enabled enhancing and tuning chiroptical sensitivity. According to the researchers their technique offers more control parameters than just changing the OAM value. Selective response to asymmetric helical light beams was qualitatively explained in terms of induced multipole moments. The presence of dichroism in achiral nanostructures offers a significant fabrication advantage over complex chiral structures and enables the development of next-generation plasmonic-based chiroptical spectroscopy and molecular sensing… read more. TECHNICAL ARTICLE
Graphical abstract. Credit: ACS Nano, September 29, 2024, XXXX, XXX, XXX-XXX