Fig. 4
From: Hyper-spectral imaging with up-converted mid-infrared single-photons
Mid-infrared (MIR) absorption analysis of polymers: (a) polystyrene sheet and (b) low-density polyethylene (LDPE). In both figures, the dashed curved lines represent rescaled FTIR spectroscopy results for comparison. The vertical dashed lines in (a) and (b) mark the wavelengths corresponding to the three spatial images shown in (c) and (d), respectively. The contrast image between selected wavelengths is presented in (e-h), demonstrating good sensitivity to the relevant C–H vibrational transitions. Each spatial image has an area of 775 \(\mu\)m by 775 \(\upmu\)m with 25 \(\upmu\)m step size.
