| 111Equation Chapter 1 Section 1Optical fiber meta-tips: Supplementary information
Maria Principe1,2,+, Marco Consales1,+, Alberto Micco1, Alessio Crescitelli3, Giuseppe
Castaldi2, Emanuela Esposito3, Vera La Ferrara4, Antonello Cutolo1, Vincenzo Galdi2,*,
and Andrea Cusano1,*
1Optoelectronic Division, Department of Engineering, University of Sannio, I-82100 Benevento, Italy
2Waves Group, Department of Engineering, University of Sannio, I-82100 Benevento, Italy
3Institute for Microelectronics and Microsystems, National Research Council, I-80131, Napoli, Italy
4UTTP-MDB, Materials and devices, ENEA — Portici Research Center, I-80055 Portici (NA), Italy
*Correspondence and requests for materials should be addressed to V.G. (email@example.com) or A.C.
+these authors contributed equally to this work
This document contains additional details on the design, fabrication and experimental characterization, as well as supplementary results. Newly introduced equations are labeled with the prefix “S”, whereas newly introduced figures and tables are referred to as “Supplementary” and are labeled with the prefix “S”; all others pertain to the main text. All references are intended as local, and those already utilized in the main text are repeated.
SUPPLEMENTARY MATERIALS AND METHODS
Design procedure and numerical modeling
Our metasurface design relies on a preliminary numerical study of the transmission coefficient pertaining toa 2-D periodic array of identical rectangular nanoholes. These numerical simulations are carried out by means of the RF module available in the finite-element-based commercial software COMSOL Multiphysics (www.comsol.com).
The periodic array is placed at the interface between two homogeneous halfspaces made of silica and air. We consider a square unit-cell with sidelengthwhich, at the operational wavelength of interest , ensures that only the fundamental (zeroth) diffraction order propagates in the two regions.The unit cell is terminated by periodic Bloch-type boundary conditions along the - and - directions. Port-type terminations are instead assumed along the incidence direction , at a distance (i.e., ambient wavelength) from the array, and matched with the zeroth-order modes for both - and -polarized illuminations. An adaptive meshing is utilized, with maximum element size of in the uniform dielectric regions, and of 15 nm in the air regions of the array; for the gold layer, a minimum number of two elements per skin depth ( at ) is employed.