High-speed near-field scanning optical microscopy with a quartz crystal resonator

We demonstrate high-speed near-field scanning optical microscopy using a tapered fiber tip that is inserted in a perforated quartz-crystal resonator. With this high-frequency dithering probe, we have obtained near-field optical images at the scanning speed of 1.3 mm/s and it takes only 0.5 s to image the surface area of $\text{100\hspace{0.17em}μ}{\mathrm{m}}^2$ for $\text{64×64}$ pixels without any compromise of spatial lateral resolution. As an application, we have obtained sequential scanning images of the diffusing microspheres in water, which shows slow change of the sample configuration in the time scale of several minutes.