Tatsuya Miyatani

Improvements in near-field optical performance using localized surface plasmon excitation by a scatterer-formed aperture

Near-field optical performance is greatly improved using our proposed near-field structure, in which a metal scatterer formed in an aperture enhances localized surface plasmon (LSP) excitation and functions as an alternative near-field light source. Based on the design through a finite-difference time-domain method, the scatterer-formed aperture is fabricated with an electron beam technique, and its near-field optical distribution is observed using a scanning near-field optical microscope. The scatterer-formed aperture enhances the near-field optical energy due to LSP excitation, thereby realizing a significant and simultaneous improvement in throughput and spatial resolution.

Development of a geometrical evaluation apparatus for ultrahigh 100 GB optical disk masters

We report on the development of a prototype system for the automatic characterization of the pit shape in optical master disks (OMDS) and its relationship with the corresponding optical readout signal. The system consists of two basic components: an optical disk drive tester (ODDT) which uses a laser beam pickup to convert physical pits on the master disk into electrical signals and an integrated atomic force microscope (AFM). In this system, the ODDT scans the OMD and records the positions of errors. Using these recorded positions, the integrated tapping-mode AFM unit then automatically positions the AFM head to the corresponding locations on the OMD and initiates a scan which serves to record topographical information of pit shape in the error regions. In an initial trial, the system was used to automatically detect and record topographical information on randomly written error patterns (1μm in length) recorded on a 12 cm diam optical disk. For each identified region, 50μm square AFM scans were then aut...

Bending of a rectangular cantilever of an atomic force microscope as a function of position along length

In order to measure quantitatively the surface stress change of a cantilever for an atomic force microscope, we studied the bending of a rectangular cantilever pushed ca. 50 nm against a hard surface as a function of the laser spot position on the cantilever and compared the result with the bending caused by the surface stress change.