Yang Jiaqi, Lan Tian
Appl Opt. 2019 Feb 1;58(4):782-786. doi: 10.1364/AO.58.000782.
Metadevices based on dielectric nanostructure with excitation of electric and magnetic resonances have shown high efficiency for polarization control compared with conventional manipulation methods, as well as plasmonic structure metadevices. Since both the electric and magnetic dipole (MD) resonances can be precisely adjusted by optimizing geometric parameters of the resonators to meet the desired wavelength, this paper proposes an approach to implement the high transmittance metadevices operating at preferred wavelengths. By employing this method, we demonstrate an all-dielectric quarter wave plate (QWP) metasurface with high transmittance (>85%) and high polarization conversion efficiency (>0.88) in a broad telecom waveband. At the same time, conversion efficiency is nearly unaffected for incident angles within 75°. With features of high transmittance, wide angle, and invertible linear to circular polarization conversion, the all dielectric QWP can be a good replacement for plasmonic metasurface devices and offers a further step in developing polarization and phase manipulation metadevices.
与传统操纵方法以及等离子体结构超表面器件相比,基于具有电和磁共振激发的介电纳米结构的超表面器件在偏振控制方面已显示出高效率。由于电偶极子和磁偶极子(MD)共振都可以通过优化谐振器的几何参数来精确调整,以满足所需波长,因此本文提出了一种实现工作在优选波长的高透射率超表面器件的方法。通过采用这种方法,我们展示了一种全介质四分之一波片(QWP)超表面,在宽电信波段内具有高透射率(>85%)和高偏振转换效率(>0.88)。同时,对于75°以内的入射角,转换效率几乎不受影响。全介质QWP具有高透射率、宽角度以及线性到圆偏振转换可逆的特点,可以很好地替代等离子体超表面器件,并为开发偏振和相位操纵超表面器件迈出了进一步的步伐。