# Chiral Metasurfaces: A Review of the Fundamentals and Research Advances
## 4 Conclusions and Outlook
Furthermore, chiral objects can interact with light differently because achiral light can locally be chiral near or across meta-atoms. The role of achiral fields and systems in the enantioselective interaction between light and matter indicates that old ideas of chiral systems should be widened. Subwavelength chiral particles can also be utilized as meta-atoms to effectively develop continuous chiral media [153; 154; 155; 156; 157; 158; 159; 160; 161; 162]. Chiral particles offer novel and improved characteristics and are candidates for use in optical materials and chiral sensing. Recent advances in chiral particles include plasmonic chirality by interacting with nanocrystals and biomolecules [159; 160; 161]; biosensing using plasmon-enhanced EM fields [157; 158]; chiral nanocrystal structures with well-controlled geometries [154; 155; 156]; understanding the clustering behavior of biomolecules using an optimal viewing angle [162]; and encoding chirality into nanoparticles using chiral molecules including peptides, DNA, and proteins with chiral conformation [163; 164; 165; 166; 167; 168; 169]. The use of chiral metasurfaces spans a multitude of disciplines, thereby promising profound advancements in the times ahead. Chiral metasurface finds utility in the realm of metabolomics enabling multiplexing polarization sensitivity using an additional degree of freedom [170; 171; 172]. Optical spin isolation, switchable holography, and amplitude modulation for LCP and RCP illumination light are among the potential applications of chiroptical metahograms [170; 171; 172]. Furthermore, the use of chiral metasurface extends to metalenses, facilitating the focusing of two images simultaneously. Chiral metasurfaces demonstrate the potential for multifunctional metalenses, including those with multi-focal length metalenses [173; 174; 175; 176; 177]. Moreover, chiral metasurfaces can be applied for imaging [24; 66; 74], chiral metamirrors [149], and various other functionalities. As described, due to high speed and accuracy and applicability in inverse design, the DL-enabled design of chiral metasurface has a lot of potential. We envision that the DL concept can be used to optimize and develop chiral metasurfaces using the required optical parameters. This offers a novel outlook for understanding and facilitating chiroptical phenomena, as well as further advancing the applications of chiroptical effects, mainly in chiral sensing [173; 174; 176; 177; 178; 179; 180], spintronics [181], and stereochemistry [182]. Chiral metasurfaces can provide precise spin-polarized electron control in spintronics, which is critical for data processing and storage. They also show promise for sensitive detection and manipulation of chiral molecules, which is important in chemistry and pharmaceuticals. However, issues such as broad spectrum sensing, scalability, efficient light-spin coupling, chemical compatibility, and enhanced detection limits must be addressed so that these applications reach their full potential [173; 174; 177; 178; 179; 180; 181; 171; 172; 173; 174; 175; 176; 177; 178; 179; 182]. Writing draft and revision of manuscript, S.A.A. ; literature search, S.A.A., S.S.; proof reading, M.S. ; supervision, D.L., M.S. ; funding acquisition, D.L. All authors have read and agreed to the published version of the manuscript. D.L. acknowledges the National Research Foundation of Korea (NRF) grant (NRF-2022R1F1A1065453) funded by the Ministry of Science and ICT (MSIT) and Regional Innovation Strategy (RIS) through the NRF funded by the Ministry of Education (MOE) in 2023 (2022 RIS-005) of Korean government. M.S. acknowledges the support from the Natural Science Foundation of Jiangsu Province (BK20220603). Not applicable. The authors declare no conflict of interest.