Premium
Labyrinth Metasurface Absorber for Ultra‐High‐Sensitivity Terahertz Thin Film Sensing
Author(s) -
JáureguiLópez Irati,
RodríguezUlibarri Pablo,
Urrutia Aitor,
Kuznetsov Sergei A.,
Beruete Miguel
Publication year - 2018
Publication title -
physica status solidi (rrl) – rapid research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.786
H-Index - 68
eISSN - 1862-6270
pISSN - 1862-6254
DOI - 10.1002/pssr.201800375
Subject(s) - terahertz radiation , figure of merit , materials science , ranging , optoelectronics , sensitivity (control systems) , electric field , wavelength , optics , thin film , nanotechnology , physics , electronic engineering , computer science , telecommunications , quantum mechanics , engineering
In this work, a labyrinth metasurface sensor operating at the low‐frequency edge of the THz band is presented. Its intricate shape leads to a high electric field confinement on the surface of the structure, resulting in ultrasensitive performance, able to detect samples of the order of tens of nanometers at a wavelength of the order of millimeters (i.e., five orders of magnitude larger). The sensing capabilities of the labyrinth metasurface are evaluated numerically and experimentally by covering the metallic face with tin dioxide (SnO 2 ) thin films with thicknesses ranging from 24 to 345 nm. A redshift of the resonant frequency is observed as the analyte thickness increases, until reaching a thickness of 20 μm, where the response saturates. A maximum sensitivity of more than 800 and a figure of merit near 4500 nm −1 are achieved, allowing discriminating differences in the SnO 2 thickness of less than 25 nm, and improving previous works by a factor of 35. This result can open a new paradigm of ultrasensitive devices based on intricate metageometries overcoming the limitations of classical metasurface sensor designs based on periodic metaatoms.