SCANNING NEAR-FIELD OPTICAL MICROSCOPY IN REFLECTION MODE IMAGING IN LIQUID

A combined atomic force microscope (AFM) and scanning near-field optic al microscope (SNOM) has been constructed to obtain images under liqui ds. In this combined AFM-SNOM an inverted ac mode configuration is use d where the AFM cantilever is driven hv exciting acoustic modes of the liquid cell. Optical images of latex spheres on a cantilever have bee n obtained under perfluorononane, butanol, and water with a lateral re solution of 100 nm. Fluorescence images of latex spheres have been obt ained under perfluorononane. The ability to image under liquids opens up a wide range of applications of near field optical microscopy in ch emistry and biology. (C) 1997 American Institute of Physics.