发表机构
University of Melbourne; Hanyang University; Sungkyunkwan University (SKKU); Institute for Basic Science (IBS)（墨尔本大学; 汉阳大学; 成均馆大学; 基础科学研究所）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过逆向设计制备硅基螺旋手性超表面，在800纳米波长下实现高达62%的实验螺旋二色性，验证了该方法用于增强结构光手性响应的可行性。
AI 中文摘要
螺旋二色性（HD）源于携带轨道角动量（OAM）的结构光与手性物质之间的相互作用，为亚波长尺度下的增强手性光学表征提供了机遇。在此，我们采用逆向设计来开发针对拉盖尔-高斯（LG）光束照射下增强HD定制的螺旋手性超表面。优化后的平面结构在800纳米波长下对相反OAM态表现出约115%的模拟HD，揭示了逆向设计几何结构所实现的强手性光学响应。优化的超表面由Si$_3$N$_4$制成，并使用定制的光学系统在受控OAM激发下进行了实验表征。单个螺旋手性超表面在800纳米附近表现出高达62%的最大实验HD，展示了单个6微米大小的手性结构产生的强OAM依赖性螺旋二色响应。尽管测得的HD值低于优化模拟值，但实验结果验证了逆向设计螺旋手性超表面用于结构光手性光学的可行性。这些发现确立了逆向设计作为工程化紧凑型手性纳米光子结构以增强与结构光相互作用的有效方法，为小型化手性光学传感和OAM分辨成像提供了潜力。
英文摘要
Helical dichroism (HD), arising from the interaction between structured light carrying orbital angular momentum (OAM) and chiral matter, offers opportunities for enhanced chiroptical characterization at the subwavelength scale. Here, we employ inverse design to develop chiral metasurfaces tailored for enhanced HD under Laguerre-Gaussian (LG) beam illumination. The optimized planar structure exhibits a simulated HD around 115% at 800 nm for opposite OAM states, revealing the strong chiroptical response enabled by the inverse-designed geometry. The optimized metasurfaces were fabricated from Si$_3$N$_4$ and experimentally characterized using a custom-built optical system with controlled OAM excitation. A single chiral metasurface exhibited a maximum experimental HD up to 62% near 800 nm, demonstrating a strong OAM-dependent helical dichroic response from a single 6-micron-large chiral structure. Although the measured HD value is lower than the optimized simulation value, the experimental result validates the feasibility of inverse-designed chiral metasurfaces for structured-light chiroptics. These findings establish inverse design as an effective approach for engineering compact chiral nanophotonic structures with enhanced interactions with structured light, offering potential for miniaturized chiroptical sensing and OAM-resolved imaging.
Comments17 pages, 4 figures
