Compressed sensing FTIR nano-spectroscopy and nano-imaging

By: Bernd Kastner, Franko Schmahling, Andrea Hornemann, Georg Ulrich, Arne Hoehl, Mattias Kruskopf, Klaus Pierz, Markus B. Raschke, Gerd Wabbeler, and Clemens Elster

Optics Express 26, 18115 (2018)

Infrared scattering scanning near-field optical microscopy (IR s-SNOM) provides for spectroscopic imaging with nanometer spatial resolution, yet full spatio-spectral imaging is constrained by long measurement times. Here, we demonstrate the application of compressed sensing algorithms to achieve hyperspectral FTIR-based nano-imaging at an order of magnitude faster imaging speed to achieve the same spectral content compared to conventional approaches. At the example of the spectroscopy of a single vibrational resonance, we discuss the relationship of prior knowledge of sparseness of the employed Fourier base functions and sub-sampling. Compressed sensing nano-FTIR spectroscopy promises both rapid and sensitive chemical nano-imaging which is highly relevant in academic and industrial settings for fundamental and applied nano- and bio-materials research.