Light absorption by an atomic force microscope probe

In this paper a probe of an atomic force microscope (AFM) served as a detector of optical radiation. We investigated absorption of optical radiation in the visible range by commercially available Si and Si₃N₄ probes. It has been shown that the radiation in the far field is mainly absorbed in the probe tip. By scanning a laser beam with a diameter of ∼ 0.7 microns by the AFM probe, a lateral resolution of ∼ 1.5 microns was demonstrated. Numerical modeling of evanescent wave absorption by AFM probes showed enhancement of the absorption in the probes as compared with a flat surface. A Si₃N₄ probe more effectively absorbs the evanescent radiation.