Date The final copy of this thesis has been examined by the signatories, and we find that both the content and the form meet acceptable presentation standards of scholarly work in the above mentioned discipline. Thesis directed by Professor Markus Raschke Scattering scanning near-field optical microscopy (s-SNOM) is a powerful technique for measuring spectroscopic properties of materials with s...

The method of fluorescence resonance energy transfer scanning near-field optical microscopy (FRET SNOM) consists in the separation of a FRET pair between an SNOM tip and a sample. The donor (or acceptor) centre is located at the tip apex and scanned in the vicinity of a sample while acceptor fluorescence (or donor-fluorescence quenching) is detected. It is shown that the spatial resolution for ...

Individual carbocyanine dye molecules in a sub-monolayer spread have been imaged with near-field scanning optical microscopy. Molecules can be repeatedly detected and spatially localized (to approximately lambda/50 where lambda is the wavelength of light) with a sensitivity of at least 0.005 molecules/(Hz)(1/2) and the orientation of each molecular dipole can be determined. This information is ...

Near-field scanning optical microscopy enables the simultaneous topographical and subdiffraction limited optical imaging of surfaces. A process is presented for the implementation of single individually engineered gold cones at the tips of atomic force microscopy cantilevers. These cantilevers act as novel high-performance optical near-field probes. In the fabrication, thin-film metallization, ...

Using a near-field scanning optical microscope (NSOM), crystals of zinc-porphyrin network materials are characterized with respect to morphology and fluorescence. Needle-shaped crystals are observed. While the topography is flat, the fluorescence intensity profile in the width direction is approximately triangular. A numerical calculation shows that differences between the topographic and optic...

Near-field scanning optical microscopy was used to observe high-resolution images of confined modes and photonic bands of planar photonic crystal ~PPC! nanocavities fabricated in active InGaAsP material. We have observed the smallest optical cavity modes, which are intentionally produced by fractional edge dislocation high-Q cavity designs. The size of the detected mode was roughly four by thre...

Near-field scanning optical microscope (NSOM or SNOM) is a form of scanning probe microscope (SPM), which is used to observe the optical properties of a sample surface with a nanometer-scale spatial resolution. Since the near-field light strongly interacts with the sample surface, or with nanometer-scale objects on the substrate's surface, NSOM is advantageous to excite only the vicinity of a s...

Polarization properties of apertureless-type scanning near-field optical microscopy (a-SNOM) were measured experimentally and were also analyzed using a finite-difference time-domain (FDTD) simulation. Our study reveals that the polarization properties in the a-SNOM are maintained and the a-SNOM works as a wave plate expressed by a Jones matrix. The measured signals obtained by the lock-in dete...

We have implemented continuous-wave two-photon excitation of near-UV absorbing fluorophores in a scanning near-field optical microscope (SNOM). The 647-nm emission of an Ar-Kr mixed gas laser was used to excite the UV-absorbing DNA dyes DAPI, the bisbenzimidazole Hoechst 33342, and ethidium bromide in a shared aperture SNOM with uncoated fiber tips. Polytene chromosomes of Drosophila melanogast...

Near-field scanning optical microscopy (NSOM) is a powerful alternative method to observe the optical intensity distributions in fabricated nanophotonic structures. Several groups have obtained NSOM images of photonic crystal (PC) [1-2]. Quite recently, we have reported the optical mode images obtained by NSOM on compact PC cavities based on fractional edge dislocations [3]. Here we report high...