Department of Optics and Photonics, National Central University, Taoyuan, 32001, Taiwan.
Sci Rep. 2023 Jan 30;13(1):1641. doi: 10.1038/s41598-023-28619-8.
We propose a hetero-nano-fin structure to further improve the efficiency of Pancharatnam-Berry phase metasurfaces. Two hetero-nano-fin types, MgF/GaN and MgF/NbO, were investigated. The overall polarization conversion efficiency (PCE) improved from 52.7 to 54% for the MgF/GaN nano-fin compared with the bare GaN nano-fin. The overall PCE of the NbO nano-fin was 1.7 times higher than that of the GaN nano-fin. The overall PCE improved from 92.4% up to 96% after the application of MgF antireflection. Moreover, the antireflection improves efficiency by an average of 4.3% in wavelengths from 450 to 700 nm. Although the increment of energy seems minimal, antireflection is crucial for a metasurface, not only enhancing efficiency but also reducing background signal of a meta-device.
我们提出了一种异质纳米鳍结构，以进一步提高 Pancharatnam-Berry 相位超表面的效率。研究了两种异质纳米鳍类型，MgF/GaN 和 MgF/NbO。与裸 GaN 纳米鳍相比，MgF/GaN 纳米鳍的整体偏振转换效率（PCE）从 52.7%提高到 54%。NbO 纳米鳍的整体 PCE 比 GaN 纳米鳍高 1.7 倍。应用 MgF 抗反射后，整体 PCE 从 92.4%提高到 96%。此外，抗反射在 450 到 700nm 的波长范围内平均提高了 4.3%的效率。虽然能量的增加似乎微不足道，但抗反射对于超表面至关重要，它不仅可以提高效率，还可以降低元器件的背景信号。
