Open AccessBi-directional terahertz-to-infrared emission from metal-coated nanostructures upon femtosecond laser irradiation
Author(s) -
Liangliang Zhang,
Tong Wu,
Jinhua Zhao,
Cunlin Zhang,
X.-C. Zhang
Publication year - 2015
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.23.025202
Subject(s) - materials science , laser , femtosecond , optics , terahertz radiation , far infrared laser , optoelectronics , surface plasmon polariton , surface plasmon , irradiation , infrared , substrate (aquarium) , plasmon , excitation , physics , oceanography , nuclear physics , geology , quantum mechanics
We report on the investigation of bi-directional terahertz-to-infrared (THz-to-IR) radiation from a metal film coated on a substrate with randomly ordered pore arrays by irradiation of femtosecond laser pulses. THz-to-IR radiation was observed both for front-side excitation (laser incident on the metal surface) and for rear-side excitation (laser incident on the substrate). In both cases, the radiation was observed both in the propagation direction of the laser beam and in the reverse direction. Considering these findings, we propose a thermal emission mechanism based on the production of surface plasmons, either delocalized (through phase-matched excitation) or localized (through surface roughness) at the air/metal and metal/substrate interfaces.