Dielectric cross-shaped resonator based metasurface for vortex beam generation in Mid-IR and THz wavelengths

Metasurfaces are engineered thin surfaces comprising two dimensional (2D) arrays of sub-wavelength spaced and sub-wavelength sized resonators. Metasurfaces can locally manipulate the amplitude, phase and polarization of light with high spatial resolution. In this study, we report numerical and exper...

Full description

Saved in:
Bibliographic Details
Published in:arXiv.org 2019-06
Main Authors: Dharmavarapu, Raghu, Izumi, Ken-ichi, Katayama, Ikufumi, Ng, SoonHock, Vongsvivut, Jitraporn, Tobin, Mark J, AleksandrKuchmizhak, Nishijima, Yoshiaki, Bhattacharya, Shanti, SauliusJuodkazis
Format: Article
Language:English
Subjects:
Electron beams
Focal plane devices
Incident light
Infrared spectroscopy
Metasurfaces
Optical components
Polarization
Resonators
Spatial resolution
Spectra
Time domain analysis
Vortices
Wave fronts
Wavelengths
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Metasurfaces are engineered thin surfaces comprising two dimensional (2D) arrays of sub-wavelength spaced and sub-wavelength sized resonators. Metasurfaces can locally manipulate the amplitude, phase and polarization of light with high spatial resolution. In this study, we report numerical and experimental results of a vortex-beam-generating metasurface fabricated specifically for infrared (IR) and terahertz (THz) wavelengths. The designed metasurface consisted of a 2D array of dielectric cross-shaped resonators with spatially varying length, thereby providing desired spatially varying phase shift to the incident light. The metasurface was found to be insensitive to polarization of incident light. The dimensions of the cross-resonators were calculated using rigorous finite difference time domain (FDTD) analysis. The spectral scalability via physical scaling of meta resonators was demonstrated using two vortex generating optical elements operating at 8.8~\(\mu\)m (IR) and 0.78~THz (Terahertz). The vortex beam generated in the mid-IR spectral range was imaged using FTIR imaging miscroscope equipped with a focal plane array (FPA) detector. This design could be used for efficient wavefront shaping as well as various optical imaging applications in mid-IR spectral range, where polarization insensitivity is desired.
ISSN:2331-8422
DOI:10.48550/arxiv.1906.10292