Open AccessTunable metasurfaces using phase change materials and transparent graphene heaters
Author(s) -
Omid Abed,
Leila Yousefi
Publication year - 2020
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.404103
Subject(s) - materials science , beam steering , graphene , optics , optoelectronics , joule heating , thermal , phase (matter) , light beam , beam (structure) , nanotechnology , physics , quantum mechanics , meteorology , composite material
Tunable metasurfaces enable us to dynamically control light at subwavelength scales. Here, using phase change materials and transparent graphene heaters, a new structure is proposed to develop tunable metasurfaces which support first-order Mie-type resonance in the near-IR regime. In the proposed structure, by adjusting the bias voltages applied to transparent graphene heaters, the crystallization levels of the phase change materials are controlled, which in turn modifies the response of the metasurface. The proposed metasurface is able to modulate the phase of the reflected wave in the range of 0° to -270° at the telecommunication wavelength of λ = 1.55 µm. A comprehensive Joule heating analysis is performed to investigate the thermal characterizations of the proposed structure. The results of this analysis show that there is a suitable thermal isolation between adjacent unit cells, making individual control on unit cells possible. The potential ability of the proposed metasurface as a beam steering device is also demonstrated. By using the proposed unit cells, a beam-steering device is designed and numerically studied. This study shows that the device can reflect a light normally incident on it in the range of ±65° with reasonably low sidelobe levels. The proposed structure can be used in developing low-cost integrated LiDARs.