A multifunction plasmonic metasurface made of metal-dielectric-metal (MDM) layers is designed, and its chiral, absorption, and refractive index sensing properties are studied numerically using finite difference time domain (FDTD) computation. Top layer of the proposed novel metasurface consists of four L-shape gold strips arranged in a specific orientational sequence into a square unit cell whose period (along X direction and Y direction) is varied from 800 to 1400 nm in a step of 200 nm. The proposed super-structure shows highly chiral behaviour with multi bands circular dichroism (CD) between ~ 600 and 1200 nm with highest CD value of about 0.4. The CD spectral response is seen to be tunable with the structural parameters such as periods and appropriate L-strip length. True chiral nature of the proposed structure is cross-checked by computing its enantiomer that shows a mirror reflection of CD response of the original structure. Multi-work functionalities are investigated by studying perfect absorption and refractive index sensing properties of the metasurface. The study shows polarization independent multi-resonance spectral absorption that reaches to ~ 100% in some cases. On the other hand, refractive index sensing study shows high sensitivity (S) of 700–750 nm/RIU (per refractive index unit) with figure of merit (FOM) of 5–10. Owing to its exotic optical properties, the novel metasurface may be considered for chip level integration for multi-purpose work functionalities.

设计了一种由金属-电介质-金属（MDM）层制成的多功能等离子超表面，并使用时差有限域（FDTD）计算对它的手性，吸收和折射率传感特性进行了数值研究。拟议的新型超颖表面的顶层由四个L形金条组成，这些金条以特定的取向顺序排列成一个正方形的晶胞，其周期（沿X方向和Y方向）以200 nm为步长从800到1400 nm变化。所提出的超结构显示出高度手性，在〜600和1200 nm之间具有多波段圆二色性（CD），最高CD值约为0.4。可以看出CD光谱响应可通过结构参数（例如周期和适当的L形条长度）进行调整。拟议结构的真实手性是通过计算其对映异构体进行交叉核对的，该对映异构体显示出原始结构CD反应的镜像。通过研究超颖表面的完美吸收和折射率传感特性，研究了多功功能。研究表明，在某些情况下，偏振无关的多共振光谱吸收达到〜100％。另一方面，折射率传感研究表明，高灵敏度（S）为700–750 nm / RIU（每折射率单位），品质因数（FOM）为5–10。由于其奇异的光学特性，可以考虑将新颖的超颖表面用于多用途工作功能的芯片级集成。