Share Email Print

Proceedings Paper

Vortex beam generation using all dielectric metasurface
Author(s): Ahmet Ozer; Nazmi Yilmaz; Hasan Kocer; Hamza Kurt
Format Member Price Non-Member Price
PDF $17.00 $21.00

Paper Abstract

Refractive and conventional optical elements such as prisms and lenses are heavy, large-sized and have limited performance in light-material interactions. Due to these severe constraints, new types of structures called metasurfaces, which are composed of subwavelength structural elements with subwavelength thicknesses, are used instead of conventional and refractive based optical elements. Metasurfaces enable unprecedented control of phase, polarization, amplitude and impedance of incident light. Thanks to these very effective features, metasurfaces have gathered remarkable attention in wavefront manipulation of photons for various applications. Earlier attempts have deployed plasmonic metasurfaces in the designs. However, the light coupled to plasmons suffers from great optical loss, which restricts high transmission efficiency, at visible wavelengths due to intrinsic heat dissipation. This problem can be overcome using all dielectric structures operating mainly in the transmission mode. Here, we numerically demonstrate vortex beam generation having donut-like intensity profile and 60% transmission efficiency. In this study, we use all dielectric metasurface that is composed of thick glass substrate and crystalline silicon which is shaped as trapezoid structure at 532 nm visible wavelength. The refractive indices of glass substrate and crystalline silicon are 1.46 and 4.15 with height of 220 nm, respectively at the designed wavelength. We have achieved 0-2π phase distribution by scaling trapezoid shaped silicon at fixed height. The interface of metasurface segmented 8 regions is filled with trapezoid shaped silicon with a π/4 phase increment in an azimuthal pattern. The obtained vortex beam can be used in various applications such as light trapping, optical tweezers, and laser beam forming.

Paper Details

Date Published: 19 September 2018
PDF: 5 pages
Proc. SPIE 10719, Metamaterials, Metadevices, and Metasystems 2018, 107192P (19 September 2018); doi: 10.1117/12.2320468
Show Author Affiliations
Ahmet Ozer, TOBB ETÜ (Turkey)
Nazmi Yilmaz, TOBB ETÜ (Turkey)
Hasan Kocer, Medical Supply and Maintenance Ctr. (Turkey)
Hamza Kurt, TOBB ETÜ (Turkey)

Published in SPIE Proceedings Vol. 10719:
Metamaterials, Metadevices, and Metasystems 2018
Nader Engheta; Mikhail A. Noginov; Nikolay I. Zheludev, Editor(s)

© SPIE. Terms of Use
Back to Top
Sign in to read the full article
Create a free SPIE account to get access to
premium articles and original research
Forgot your username?