INSTRUMENTAL DEVELOPMENTS AND RECENT EXPERIMENTS IN NEAR-FIELD OPTICAL MICROSCOPY

Recent advances in the understanding of light propagation in small dim ensions as well as in instrumentation make scanning near-field optical microscopy (SNOM) a very promising tool for studying optical phenomen a on a nanometer scale. In this talk, we will demonstrate experiments carried out with the recently developed tunneling near-field optical m icroscope. We found superior image contrast, as compared with images t aken with conventional aperture SNOM, along with the high resolution c ommonly achieved with fiber probes. This work was motivated by the the oretical investigations presented in Dr. Pohl's talk. We will further describe two recently built instruments. The first is a scanning tunne ling optical microscope combined with a scanning force microscope. The second instrument is an aperture-type SNOM mounted on the sample stag e of a conventional inverted optical microscope. Of particular interes t to us is imaging with polarization contrast. One of the goals is to study liquid-crystal films which have been micropatterned with the hel p of a force microscope tip. These samples are promising as waveguides and potential electro-optical devices. Additionally, they represent v ery convenient test samples for polarization SNOM.