|
|
|
|
SUBTHEMES
■ Near-field Optical Recording
Fine light spot as small as 1/10 or less in diameter can be formed by using a near-field optical probe. However, this method has some demerits such as very low intensity and need to keep the distance between the probe tip and the recording surface at less than 10 nm or so. The ultra-high density write/read system is studied both experimentally and theoretically to overcome such restrictions.
■ Development of Near-field Optical Recording Media
There is very little data on the recording materiels suited for near-field optical recording. In the first step, the phase change recording materials will be studied, later followed by optomagnetic and organic materials.
■ Development of Near-field Optical Device Technology
Aiming at the development of practical recording system, an aperture to output and accept near-field light is constructed on a planar substrate. The process of making planar aperture array is studies to build a foundation for constructing a floating head.
■ Development of Ultra-Precision Pit Measuring Technology
As a part of "R&D of Nanometer Controlled Optical Disk System" (under the Application Industrial Technology Frontier Program), the application of near-field optical probe technology to the evaluation of fine recording pits is under way.
REPRESENTATIVE ACHIEVEMENTS
■ Readout of Phase Change Recording Marks by a Near-Field Optical Probe
Phase change recording marks were observed with a near-field optical probe, and could be successfully detected at a high contrast. While the level difference of a mark is as small as 2 nm or less, the change in refractive index was detected.
■ Development of Super-RENS System
If an antimony mask is formed in a disk, antimony turns transparent while being irradiated with high intensity light. When the disk is irradiated with laser light, a transparent area about 1/10 of spot diameter is formed, which serves as an exit aperture of near-field light. In this way, it has become possible to write and read fine marks as small as 100 nm with laser light of wavelength 680 nm. This system was designated as Super-RENS (= Super-Resolution Near-Field Structure).
|
|
