An improved concept of the advanced SIL and its compensation OL of composite effective NA over 1.7 has
been designed and manufactured to achieve wider assembling tolerances, higher data capacities and better signal quality.
Very clear readout signals were measured from a 25 GB BD-like ROM media with 3 um cover layer and the applying
feasibility of the advanced SIL system in near field optical storage was confirmed. With this novel advanced SIL system
and multilayer media concept, total capacity over 500 GB per disc was expected to be accomplished.
Gap servo systems based on one of near field technologies are generally using the 1-beam push pull method to generate servo signal and this causes the optical DC offset problem in servo signal. In this paper, we presented new method of track error generation using the proposed GELP signal for the gap servo near field optical storage systems. By using the GELP signal and 2-divided photo-detector for the gap error signal detection, test result shows the optical DC offset in track error signal generated from lens movement could be eliminated.
A prototype of ultra small optical drive was studied and developed in order to see the feasibility of mobile application, which is targeted to be attachable into the PCMCIA II slot in small mobile devices. A new design and fabrication technology of optical flying head (OFH) for first surface MO recording was studied, and an effective OFH precisely equipped with high NA lens and MO coil was developed based on miniaturization technology. Design consideration of small form factor optical drive is discussed. Some technical issues and barriers in designing and manufacturing the OFH are introduced. Head-disk interface for reliability and flying stability on plastic disk media was tested and evaluated. Basic tracking and read-write performances in a test bed system were tested.