Abstract

Near-field optical microscopy (by scattering from an AFM tip, s-SNOM) returns local absorbance from a tiny volume of only (20 nm)³ under the tip apex, thus enabling VIS-to-IR-to-THz mapping at exciting 20 nm resolution. The mid-infrared is ideal for nanoscale chemical recognition by vibrational and phonon contrasts (FTIR). Near-field techniques now offer nano-FTIR, i.e. FTIR at nanometric spatial resolution. For this, broadband coherent MIR sources are essential and higly desirable, especially when combined with dual-comb operation. Application highlights will be presented of finding and characterizing natural nanoscale inhomogeneities, chemical as well as structural, in organic solar-conversion films, in bone/shell biomineral matter, and in slices through a cometary dust particle.—Nano-FTIR is no less than the continued success story of FTIR-based chemical analysis into resolutions hundreds, if not thousands of times better than previously attainable. It is a highly welcome solution to nanoanalysis requirements in all nanotechnologies and nanosciences.

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