Air-bearing surface design of an optical flying head considering dynamic characteristics

Abstract

The near-field recording (NFR) system requires the clearance between a slider and disk surface in order to maintain the significant effect on the evanescent wave. The optical flying head (OFH) should also have a small pitch to control the contamination effect. The larger the gap between the leading edge of the slider and the disk, the more the particles come into solid immersion lens (SIL), thereby causing a negative influence on the NFR system. However, the flying stability turns out to be ineffective as the pitch angle reduces. Accordingly, it is necessary to consider dynamic characteristics of OFH in air-bearing surface (ABS) design. The objective of the ABS design is such that the flying height (FH) of the OFH should be as flat as possible over the inner diameter (ID) and outer diameter (OD) of the disk, and FH should be controlled at about 50 nm for both ID and OD in the static state. The better NFR system can also be obtained by a smaller modulation. The numerical optimization in the static state is first carried out, and the dynamic optimization is subsequently performed based on the static optimal model. The dynamic simulation and experiments are additionally performed to verify the proposed design optimization results.