Compressive nano-FTIR chemical mapping

Abstract Nano-Fourier-transform infrared spectroscopy (nano-FTIR) combines with scanning probe microscopy (SPM) techniques and enables spectroscopic imaging of molecular electronic properties matter at nanometer spatial resolution. The can be used to derive chemical mappings, i.e. the distribution concentrations species contained in a given sample. However, due sequential principle underlying SPM, recording complete spectrum over large area leads long measurement times. Furthermore, acquired often contains additional signals from lineshape effects that are not explicitly accounted for. A compressive mapping approach is proposed for undersampled nano-FTIR data utilizes sparsity these spectral domain. projection technique standard compressed sensing, followed by spatially regularized regression. Using real measurements superimposed simulated interferograms representing species, it demonstrated procedure performs well even cases which sparse exhibit strong overlap.