In Photo-induced Force Microscopy (PiFM) the near-field signal resulting from the surface illumination is detected via the interaction with the AFM cantilever. Unlike conventional Near-field Scanning Optical Microscopes (NSOM), both fiber-based and scattering-based, where much research is dedicated to suppress the background signal, in PiFM, no light signal is detected. In this sense PiFM is a light-background-free optical nano-spectroscopy technique that is promising for broadband operation and relaxes many of the illumination constraints of other NSOM techniques.
I will first introduce tests experiments that highlight the working principles behind PiFM. Then, I will show results from ongoing experiments of PiFM on different materials, ranging from photo-sensitive polymers to 2D van der Waals materials.
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