Reconfigurable metalens with dual-linear-focus phase distribution

A reconfigurable metalens with dual-liner-focus (DLF) phase distribution is proposed. When the incident light is at the wavelength of 300 & mu;m in the right circularly polarized (RCP) mode, the single-layer reconfigurable metalens with DLF phase distribution shows excellent focus performance. While the double-layer reconfigurable metalens with DLF phase distribution exhibits high-quality focusing characteristics, whose focal length can be tuned from 1.48 cm to 2.98 cm. The relationship between the focal length and the distance between phase block groups is calculated with a linearity of 0.9966 correlation coefficient. Furthermore, a metalens with DLF phase distribution is presented to possess polarization controllable bifocal and varifocal characteristics. The focus left circularly polarized (LCP) and RCP waves with different focal lengths can be actively tuned from 1.79 cm to 2.66 cm and from 1.33 cm to 2.07 cm, respectively. The proposed reconfigurable metalens with DLF phase distri-bution opens an avenue to design bifocal and varifocal metalens without the need of fabricating on flexible substrate or stretching in an omnidirectional direction uniformly. Given the merits of the proposed DLF design of reconfigurable metalens, it is potentially applicable in a diversity of advanced imaging applications.

Automated summary

A reconfigurable metalens with dual-liner-focus (DLF) phase distribution is proposed, which exhibits excellent focus performance at a wavelength of 300 μm in the right circularly polarized (RCP) mode. The focal length of the double-layer reconfigurable metalens with DLF phase distribution can be tuned from 1.48 cm to 2.98 cm, with a high-quality focusing characteristics. Additionally, a metalens with DLF phase distribution is presented to possess polarization controllable bifocal and varifocal characteristics.