title: Modulated near-field spectral extraction of broadband mid-infrared signals with a ceramic light source.
abstract: 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).
authors.affiliation: Department of Earth and Space Science, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka, 560-0043, Japan. mishikawa@ess.sci.osaka-u.ac.jp
authors.forename: Michio
authors.initials: M
authors.lastname: Ishikawa
authors.forename: Makoto
authors.initials: M
authors.lastname: Katsura
authors.forename: Satoru
authors.initials: S
authors.lastname: Nakashima
authors.forename: Kento
authors.initials: K
authors.lastname: Aizawa
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Inoue
authors.forename: Hidekazu
authors.initials: H
authors.lastname: Okamura
authors.forename: Yuka
authors.initials: Y
authors.lastname: Ikemoto
mesh_terms: D002516:Ceramics / Q000737:chemistry*; D003198:Computer Simulation; D004867:Equipment Design; D006046:Gold / Q000737:chemistry; D007259:Infrared Rays; D008029:Lighting / Q000295:instrumentation* / Q000379:methods; D008853:Microscopy / Q000295:instrumentation* / Q000379:methods; D008855:Microscopy, Electron, Scanning; D008962:Models, Theoretical; D017550:Spectroscopy, Fourier Transform Infrared / Q000295:instrumentation* / Q000379:methods
chemical_list: D006046:Gold