Heterodyne detection for apertureless near-field scanning optical microscopy was used to study periodic gold nanowell arrays. Optical near-field amplitude and phase signals were obtained simultaneously with the topography of the gold nanowells and with different polarizations. Theoretical calculations of the near-fields were consistent with the experiments; in particular, the calculated amplitu...

Graphene oxide (GO) thin films were simply deposited on fluorine doped tin oxide (FTO) substrate via a low-voltage electrodeposition. The GO and GO thin films were characterized by Zeta Potential, X-ray diffraction, Ultraviolet-Visible spectroscopy, atomic force microscopy, Fourier transform infrared spectroscopy, field emission scanning electron microscopy and energy dispersive X-ray spectrosc...

In this review we describe fundamentals of scanning near-field optical microscopy with aperture probes. After the discussion of instrumentation and probe fabrication, aspects of light propagation in metal-coated, tapered optical fibers are considered. This includes transmission properties and field distributions in the vicinity of subwavelength apertures. Furthermore, the near-field optical ima...

Scattering-type scanning near-field optical microscopy provides access to super-resolution spectroscopic imaging of the surfaces of a variety of materials and nanostructures. In addition to chemical identification, it enables observations of nano-optical phenomena, such as mid-infrared plasmons in graphene and phonon polaritons in boron nitride. Despite the high lateral spatial resolution, scat...

Light microscopy has greatly advanced our understanding of nature. The achievable resolution, however, is limited by optical wavelengths to approximately 200 nm. By using imaging and labeling technologies, resolutions beyond the diffraction limit can be achieved for specialized specimens with techniques such as near-field scanning optical microscopy, stimulated emission depletion microscopy, an...

We report the application of an optical microscope equipped with a high-resolution dark-field condenser for detecting dynamic responses of cellular nanostructures in real time. Our system provides an easy-to-use technique to visualize biological specimens without any staining. This system can visualize the dynamic behavior of nanospheres and nanofibers, such as F-actin, at the leading edges of ...

Scanning near-field optical microscopy is one of the most effective techniques for spectroscopy nanoscale systems. However, inferring constants from measured signal can be challenging because a complicated and highly nonlinear interaction between scanned probe sample. Conventional fitting methods applied to this problem often suffer lack convergence or require human intervention. Here we develo...

Diffraction limits standard optical microscopy to a spatial resolution of about half the wavelength of light. We present novel microscopy techniques for imaging semiconductor materials and devices at better than diffraction-limited spatial resolution and observe previously inaccessible phenomena. We discuss the methods and results for Numerical Aperture Increasing Lens (NAIL) and Near-field Sca...

We discuss our recent results as well as planned experiments for obtaining molecular resolution in optical microscopy. By combining single molecule spectroscopy and scanning probe microscopy we have demonstrated optical microscopy with a single-molecule light source. We also sketch a method for the use of an inhomogeneous static electric field for determining the position of a molecule in all t...