Design of multi-wavelength dielectric metasurfaces using finite element software


Dielectric metasurfaces have great potential in compact optical systems. Most researchers use Finite Difference Time Domain (FDTD) based tools, most commonly Lumerical FDTD to calculate phase information, as well as model the behavior of light as it travels through the element. In this paper, we explore the use of a Finite Element Method (FEM) based tool that may be more easily available, namely COMSOL Multiphysics software. A step-by-step design approach is presented to help researchers wanting to use metasurfaces for their work. Both monochromatic and two-wavelength system designs are explained in detail. In the former case, a cylindrical metasurface unit cell is simulated in COMSOL and the results are found to match results carried out using FDTD methods. Further, a spherical lens and an axicon or conical lens that works at two different wavelengths (1300 nm and 1550 nm) are designed. Their functionality is verified through simulation in COMSOL. In this design, coupled rectangular dielectric resonators are used as the unit cell structure. By implementing these specific optical functions, the use of COMSOL as a numerical tool in modeling dielectric metasurfaces is established.

Asian Journal of Physics
Jerin Geogy George
Jerin Geogy George
Research Scholar

My research interests include meta-optics, computational electromagnetics, dielectric metasurfaces, deep learning