Abstract
Strong circular dichroism in absorption in the near-infrared wavelength range is realized by designing binary-pattern chiral plasmonic metasurfaces via the micro-genetic algorithm optimization method. The influence of geometric parameter modifications in the binary-pattern nanostructures on the circular dichroism performance is studied. The strong circular dichroism in absorption is attributed to the simultaneous excitation and field interference of the resonant modes with relative phase delay under linearly polarized incident light. This work provides a universal design method toward the on-demand properties of chiral metasurfaces, which paves the way for future applications in chemical and biological sensing, chiral imaging and spectroscopy.
Highlights
Chiral structures are well known for lacking any mirror symmetry
Manually conducted metamaterial design is usually intended for the specific design application, which is not efficient to serve as a universal design method
The proposed design method offers great potential to realize on-demand chiral metasurfaces with high performance, which are very attractive for applications in chemical and biological sensing, chiral imaging and spectroscopy
Summary
Chiral structures are well known for lacking any mirror symmetry. Unlike chiral molecules or materials in nature with weak chirality, artificially designed chiral metamaterials, for instance, two-dimensional (2D) anisotropic chiral metamaterials [1,2,3,4], dual-layer or multilayer twisted structures [5,6,7,8,9], helical meta-atoms [10,11] and even achiral planar metasurfaces [12,13] can achieve giant chiral properties including optical rotation, circular dichroism and asymmetric transmission. The mechanism of generating the strong circular dichroism with complex binary-pattern structures has not been thoroughly. We employ the micro-genetic algorithm to optimize the design of binary-pattern chiral plasmonic metasurfaces for achieving strong circular dichroism in absorption (CDA), with distinct absorption values for left- and right-handed circularly polarized (LCP and RCP) light. The influence of geometric parameter modifications on the circular dichroism is studied by involving single-pixel changes in the binary-pattern nanostructures. The proposed design method offers great potential to realize on-demand chiral metasurfaces with high performance, which are very attractive for applications in chemical and biological sensing, chiral imaging and spectroscopy
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
