Scanning Near-field Fluorescence Microscopy and Nanoscopic Fluorescence Spectroscopy in Combination with a Non-contact Scanning Force Microscope

The resolution of scanning near-field optical microscopy (SNOM) is determined by the dimensions of the microscopic light source (or detector) and the probe-to-sample separation rather than the diffraction limit. In the present microscope, we took advantage of scanning force microscopy (SFM) with a vibrating cantilever holding an optical fiber tip not only to give a simultaneous SFM topographic image but also to control the separation for SNOM without mechanical damages of the sample. By the precise control of the separation of the tip within 100 nm from the sample surface, we demonstrate here that this combined non-contact SFM and SNOM method can be used as fluorescence microscopy and nanoscopic fluorescence spectroscopy with a resolution of ∼100 nm.