Open AccessHyperspectral time-domain terahertz nano-imaging
Author(s) -
Neda Alsadat Aghamiri,
Florian Huth,
Andreas Huber,
Alireza Fali,
Rainer Hillenbrand,
Yohannes Abate
Publication year - 2019
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.27.024231
Subject(s) - hyperspectral imaging , terahertz radiation , terahertz spectroscopy and technology , optics , materials science , near field scanning optical microscope , optoelectronics , microscopy , nanoscopic scale , photonics , semiconductor , image resolution , scanning electron microscope , physics , optical microscope , nanotechnology , remote sensing , geology
Terahertz (THz) near-field microscopy has wide and unprecedented application potential for nanoscale materials and photonic-device characterization. Here, we introduce hyperspectral THz nano-imaging by combining scattering-type scanning near-field optical microscopy (s-SNOM) with THz time-domain spectroscopy (TDS). We describe the technical implementations that enabled this achievement and demonstrate its performance with a heterogeneously doped Si semiconductor sample. Specifically, we recorded a hyperspectral image of 40 by 20 pixels in 180 minutes and with a spatial resolution of about ~170 nm by measuring at each pixel with a time domain spectrum covering the range from 0.4 to 1.8 THz. Fitting the spectra with a Drude model allows for measuring-noninvasively and without the need for Ohmic contacts-the local mobile carrier concentration of the differently doped Si areas. We envision wide application potential for THz hyperspectral nano-imaging, including nanoscale carrier profiling of industrial semiconductor structures or characterizing complex and correlated electron matter, as well as low dimensional (1D or 2D) materials.