Showing papers by "Din Ping Tsai published in 1998"

Tapping-mode tuning fork force sensing for near-field scanning optical microscopy

Abstract: A tapping-mode tuning fork force-sensing method for near-field scanning optical microscope is reported. Use of the tapping-mode tuning fork with mechanically asymmetric excitation generates better stability and sensitivity than in the shear force mode. Comparison of force curves for the two methods demonstrate that the tapping-mode tuning fork method provides a simpler and more sensitive method for near-field measurements. The method is demonstrated by imaging a sample consisting of 500 nm standard polystyrene spheres on silica in both air and water.

Controllable fabrication of bent near-field optical fiber probes by electric arc heating

Abstract: We describe the construction of a high voltage electric arc puller for controllable fabrication of bent near-field optical fiber probes. Various probes with bent angles ranging from 30° to 75° and bent lengths between 600 and 900 μm were successfully produced. The tip diameters achieved are between 100 and 200 nm. These bent type probes can be made into cantilevered probes that can be used for any dynamic mode atomic force microscope, and make the construction of a scanning near-field optical microscope easily attainable.

Ultrahigh-density optical recording using a scanning near-field optical microscope

Abstract: Near-field scanning optical microscope (NSOM) system with a bent or a straight optical fiber probe has been successfully developed to perform optical recording on the surface of cyanine (C35H35CIN2-O4) dye layer or Ge21Te26Sb53 phase change (PC) thin film. Optical writing bits < 40 nm on the cyanine dye layer of a commercial compact disk-recordable were shown by atomic force microscope images of our tapping mode NSOM. For an vertical reflection mode NSOM, both optical writing and reading can be achieved on Ge21Te26Sb53 PC thin film, and the diameter of 500 nm recording bits are shown.© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Near-field optical characterization of visible multiple quantum well semiconductor lasers

Abstract: Both collection and excitation modes of scanning near-field optical microscopy (SNOM) were used to study a low power visible multiquantum-well laser diode (LD) Collection mode SNOM provides the near-field optical propagating intensity distribution at the facet of LD Excitation mode SNOM gives local photoconductivity information of the structure of LD facet Results show highly localized spatial correlation of LD structure and its optical performance at the facet Different sizes of apertures were used in both modes, and results of near-field interactions can be quite different Results show obvious difference of photocurrent distribution caused by the different sizes of apertures in excitation mode Two wavelengths of 5435 nm and 6328 nm were used in excitation mode SNOM It can be deduced from the two pump photon energies that there exists defect level in the energy range of 60 - 380 meV below the conduction band edge in the n-(Al07Ga03)05In05P cladding layer In addition to the highly localized images of topography, optical output, and optical beam induced current at the facet of LD, local near- field optical spectroscopy was performed as well Spatially resolved near-field optical spectra of both stimulated and spontaneous emissions were obtained at the facet of LD Longitudinal modes of stimulated emission of LD were observed locally© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering Downloading of the abstract is permitted for personal use only