Open AccessModulated near-field spectral extraction of broadband mid-infrared signals with a ceramic light source
Author(s) -
M. Ishikawa,
Masahiro Katsura,
Satoru Nakashima,
Kento Aizawa,
Tsutomu Inoue,
Hidekazu Okamura,
Yuka Ikemoto
Publication year - 2011
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.19.012469
Subject(s) - optics , materials science , scattering , near field scanning optical microscope , spectrometer , infrared , signal (programming language) , forward scatter , light scattering , optical microscope , scanning electron microscope , physics , computer science , programming language
In order to obtain broadband near-field infrared (IR) spectra, a Fourier-transform IR spectrometer (FT-IR) and a ceramic light source were used with a scattering-type scanning near-field optical microscope (s-SNOM). To suppress the background (far-field) scattering, the distance between the scattering probe and the sample was modulated with frequency Ω by a piezo-electric actuator, and the Ω component was extracted from the signal with a lock-in detection. With Ω=30 kHz, a peak-to-peak modulation amplitude of 198 nm, and a probe with smooth surface near the tip, broadband near-field IR spectra could be obtained in the 1200-2500 cm(-1).