Infrared near-field spectroscopy of trace explosives using an external cavity quantum cascade laser

Ian M. Craig, Matthew S. Taubman, A. Scott Lea, Mark C. Phillips, Erik E. Josberger, Markus B. Raschke

Research output: Contribution to journalArticlepeer-review

30 Scopus citations

Abstract

Utilizing a broadly-tunable external cavity quantum cascade laser for scattering-type scanning near-field optical microscopy (s-SNOM), we measure infrared spectra of particles of explosives by probing characteristic nitro-group resonances in the 7.1-7.9 μm wavelength range. Measurements are presented with spectral resolution of 0.25 cm-1, spatial resolution of 25 nm, sensitivity better than 100 attomoles, and at a rapid acquisition time of 90 s per spectrum. We demonstrate high reproducibility of the acquired s-SNOM spectra with very high signal-to-noise ratios and relative noise of <0.02 in self-homodyne detection.

Original languageEnglish (US)
Pages (from-to)30401-30414
Number of pages14
JournalOptics Express
Volume21
Issue number25
DOIs
StatePublished - Dec 16 2013
Externally publishedYes

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics

Fingerprint

Dive into the research topics of 'Infrared near-field spectroscopy of trace explosives using an external cavity quantum cascade laser'. Together they form a unique fingerprint.

Cite this