Open AccessIntense thermal terahertz-to-infrared emission from random metallic nanostructures under femtosecond laser irradiation
Author(s) -
Liangliang Zhang,
Kaijun Mu,
Jinhua Zhao,
Tong Wu,
Hai Wang,
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.23.014211
Subject(s) - materials science , femtosecond , surface plasmon polariton , laser , surface plasmon , optics , optoelectronics , terahertz radiation , irradiation , infrared , plasmon , physics , nuclear physics
We report intense (~10 mW), ultra-broadband (~150 THz wide), terahertz-to-infrared, Gaussian-wavefront emission from nanopore-structured metallic thin films under femtosecond laser pulse irradiation. The proposed underlying mechanism is thermal radiation. The nanostructures of the metal film are produced by random holes in the substrate. Under pulse-train femtosecond laser irradiation, we found dramatically enhanced optical absorption, with an absorptivity that was equal to as much as 95% of the metallic surface nanostructure, due to both an antireflection mechanism and dissipation of excited surface plasmon polaritons into the metal surface.